Document:

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                Form of Universal Warrant Agreement                  Exhibit 4.4

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                             INDEX WARRANT AGREEMENT

                         dated as of ________ __, 200__

                                     between

                                     UBS AG

                                       and

                    [NAME OF WARRANT AGENT], as Warrant Agent

                           ___________________________

                    [Name of Index] Index [Put/Call] Warrants

                           Expiring ________ __, 200__

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                                TABLE OF CONTENTS

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PARTIES.....................................................................    1
RECITALS....................................................................    1

                                    ARTICLE I

             ISSUANCE OF WARRANTS AND FORM, EXECUTION, DELIVERY AND
                      REGISTRATION OF WARRANT CERTIFICATES

Section 1.01.    The Warrants; Issuance of Warrants;
                 Book-Entry Procedures; Successor Depository................    1
Section 1.02.    Form; Denominations; Execution, Countersignature, Delivery
                 and Dating of Global Warrant Certificates..................    4
Section 1.03.    Definitive Warrant Certificates............................    6
Section 1.04.    Maintenance of Warrant Register; Registration of Transfers
                 and Exchanges of Global Warrant Certificates...............    8
Section 1.05.    Mutilated, Destroyed, Lost and Stolen Warrant Certificates.   10
Section 1.06.    Cancellation of Warrants...................................   11

                                   ARTICLE II

               [EXERCISE PRICE,] DURATION AND EXERCISE OF WARRANTS

Section 2.01.    Duration of Warrants; Method of Exercise; Minimum
                 [and Maximum] Exercise Amounts; Notice of Exercise.........   12
Section 2.02.    Exercise of Warrants.......................................   15
Section 2.03.    Automatic Exercise of Warrants.............................   24
[Section 2.04.   Cancellation of Warrants...................................   26
Section 2.05.    Discontinuance or Modification of Index....................   27
Section 2.06.    Designation of Agent for Receipt of Notice.................   28
[Section 2.07.   Extraordinary Events.......................................   28
[Section 2.08.   Temporary Suspension of the Right to Exercise the Warrants.   28
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                                   ARTICLE III

                 OTHER PROVISIONS RELATING TO RIGHTS OF HOLDERS

Section 3.01.    Treatment of Holders.......................................   28
Section 3.02.    Holder or Owner of Warrant May Enforce Rights..............   29

                                   ARTICLE IV

                          CONCERNING THE WARRANT AGENT

Section 4.01.    Warrant Agent..............................................   29
Section 4.02.    Certain Duties of the Warrant Agent........................   30
Section 4.03.    Conditions of Warrant Agent's Obligations..................   30
Section 4.04.    Compliance With Applicable Laws............................   33
Section 4.05.    Corporate Warrant Agent Required; Eligibility..............   33
Section 4.06.    Resignation and Removal; Appointment of Successor..........   34
Section 4.07.    Acceptance of Appointment by Successor.....................   35
Section 4.08.    Merger, Conversion, Consolidation or Succession to Business   36

                                    ARTICLE V

                CONSOLIDATION, MERGER, SALE, LEASE OR CONVEYANCE

Section 5.01.    Consolidations and Mergers of the Corporation and Sales,
                 Leases and Conveyances Permitted Subject to Certain
                 Conditions.................................................   36

                                   ARTICLE VI

                             SUPPLEMENTAL AGREEMENTS

Section 6.01.    Amendment of Index Warrant Agreement.......................   38
Section 6.02.    Form of Approval of Supplemental Agreements by Owners
                 or Holders.................................................   40
Section 6.03.    Effect of Supplemental Agreements..........................   40
Section 6.04.    Reference in Warrants to Supplemental Agreements...........   40
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                                   ARTICLE VII

                          COVENANTS OF THE CORPORATION

Section 7.01.    Listing of Warrants on National Securities Exchange........   40
Section 7.02.    Governmental Approvals.....................................   41
Section 7.03.    Payment of Cash Settlement Value [or Cancellation Amount]..   41
Section 7.04.    Maintenance of Office or Agency; Unclaimed Moneys..........   41
Section 7.05.    Corporate Existence........................................   42

                                  ARTICLE VIII

                                  MISCELLANEOUS

Section 8.01.    Reopening of Issue of Warrants.............................   43
Section 8.02.    Payment of Taxes...........................................   43
Section 8.03.    Notices and Demands to the Corporation and Warrant Agent...   43
Section 8.04.    Addresses for Notices......................................   43
Section 8.05.    Notices to Owners and Holders..............................   43
Section 8.06.    GOVERNING LAW..............................................   44
Section 8.07.    Benefits of Index Warrant Agreement........................   44
Section 8.08.    Successors and Assigns.....................................   44
Section 8.09.    Index Warrant Agreement and Warrants Solely Corporate
                 Obligations................................................   44
Section 8.10.    Severability...............................................   45
Section 8.11.    Headings...................................................   45
Section 8.12.    Counterparts...............................................   45
Section 8.13.    Inspection of Index Warrant Agreement......................   45
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                                    EXHIBITS

Exhibit A        Form of Warrant Certificate

Exhibit B-1      Form of Exercise Notice from Depository Participant
Exhibit B-2      Form of Exercise Notice from Holder of Definitive Warrant
                 Certificate
Exhibit C        Form of Rejection Notice
Exhibit D        Form of Confirmation of Exercise
Exhibit E-1      Form of Depository Participant Certificate
Exhibit E-2      Form of Holder Certificate

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                             INDEX WARRANT AGREEMENT

            INDEX WARRANT AGREEMENT, dated as of ________ __, 200__ (as
modified, amended or supplemented, this "Agreement"), between UBS AG, a
corporation organized and existing under the laws of Switzerland (the
"Corporation"), and [NAME OF WARRANT AGENT], a [banking association]
[corporation] organized and existing under the laws of ______________, as
Warrant Agent (the "Warrant Agent").

                              W I T N E S S E T H:

            WHEREAS, the Corporation proposes to sell [put] [call] warrants
(each, a "Warrant") representing the right to receive from the Corporation an
amount in [U.S. dollars (specify other currency if applicable)] to be determined
by reference to [decreases] [increases] in the [(insert name of security index
or describe portfolio of specified stocks or other securities)] (the "Index");
and

            WHEREAS, the Corporation desires the Warrant Agent to act on behalf
of the Corporation, and the Warrant Agent is willing so to act, in connection
with the issuance, transfer, exchange, exercise and cancellation of the
Warrants, and the Corporation desires to set forth herein, among other things,
the provisions of the Warrants and the terms and conditions under which they may
be issued, transferred, exchanged, exercised and canceled;

            NOW, THEREFORE, in consideration of the premises and of the mutual
agreements herein contained, the parties hereto agree as follows:

                                   ARTICLE I

                         ISSUANCE OF WARRANTS AND FORM,
                      EXECUTION, DELIVERY AND REGISTRATION
                             OF WARRANT CERTIFICATES

            Section 1.01. The Warrants; Issuance of Warrants; Book-Entry
Procedures; Successor Depository. (a) Each Warrant shall represent the right,
subject to the provisions contained herein and therein, to receive the Cash
Settlement Value (as defined in Section 2.02(g)) [or
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the Cancellation Amount (as defined in Section 2.04(b)), as the case may be,] of
such Warrant. Such Cash Settlement Value [or Cancellation Amount, as the case
may be,] shall be payable in [U.S. dollars (specify other currency if
applicable)]. In no event shall any registered holder of a Warrant (each, a
"Holder") or any Owner (as defined in Section 1.01(c)) be entitled to receive
any interest on any Cash Settlement Value [or Cancellation Amount, as the case
may be], and the Warrants shall not entitle the Holders or Owners thereof to any
of the rights of the holder of any of the securities on which the Index is based
(the "Underlying Securities") or any other securities. No Warrant shall require
or entitle the Holder or Owner thereof to sell, deliver, purchase or take
delivery of any Underlying Securities or any other securities to or from the
Corporation, nor shall the Corporation be under any obligation to purchase or
take delivery of, or sell or deliver, any such securities to or from the Holders
or Owners thereof.

            (b)   The Warrants shall constitute direct, unconditional and
unsecured obligations of the Corporation.

            (c)   The Warrants shall initially be issued in book-entry form and
represented by one or more global certificates (each, a "Global Warrant
Certificate"). Owners of beneficial interests in a Global Warrant Certificate
(each, an "Owner") shall not be entitled to receive definitive certificates
evidencing the Warrants; provided, however, that the Corporation shall issue
Warrants in definitive form (each, a "Definitive Warrant Certificate", and with
the Global Warrant Certificates, the "Warrant Certificates") in exchange for a
Global Warrant Certificate if (i) the Depository (as defined in Section 1.01(d))
has notified the Corporation that it is unwilling or unable to continue as
Depository for such Global Warrant Certificate or if at any time it has ceased
to be a clearing agency registered under the Securities Exchange Act of 1934, as
amended, at a time when it is required to be so registered in order to act as
Depository, and a successor Depository is not appointed by the Corporation
within 90 days, (ii) the Corporation at any time shall determine to have the
Warrants represented by Definitive Warrant Certificates and shall execute and
deliver to the Warrant Agent a written order signed in the name of the
Corporation by its Chairman of the Board, its

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Vice Chairman, its President or a Vice President, and by its Treasurer, an
Assistant Treasurer, its Secretary or an Assistant Secretary (each such order, a
"Corporation Order") stating that the Corporation wishes to issue Warrants in
definitive form in exchange for such Global Warrant Certificate, or (iii) there
shall have occurred and be continuing a default in the payment of the Cash
Settlement Amount [or Cancellation Amount, as the case may be,] with respect to
the Warrants. In any such instance, and in accordance with the provisions of
this Agreement, each Owner shall be entitled to have registered in its name the
number of Warrants in definitive form equivalent to such Owner's beneficial
interest in such Global Warrant Certificate and shall be entitled to physical
delivery of Definitive Warrant Certificates representing such Warrants by the
Depository Participant or Indirect Participant (each as defined in Section
1.01(d)) through which such Owner's beneficial interest is reflected.

            (d)   Each Global Warrant Certificate shall initially be registered
in the name of, and the Holder of each Warrant represented by such Global
Warrant Certificate shall be, [The Depository Trust Company] or its agent (the
"Depository", which term shall include any nominee of the Depository and any
successor depository selected by the Corporation as provided in Section
1.01(e)), and shall be deposited with the Depository or its agent for credit to
the accounts of the Depository Participants as shown on the records of the
Depository from time to time. The Warrant holdings of Depository Participants
shall be recorded on the books of the Depository. The Warrant holdings of
Indirect Participants and of Owners who are customers of Depository Participants
shall be reflected on the books and records of such Depository Participants and
shall not be known to the Warrant Agent, the Corporation or the Depository. The
Warrant holdings of Owners who are customers of Indirect Participants shall be
reflected on the books and records of such Indirect Participants and shall not
be known to the Warrant Agent, the Corporation, the Depository Participants or
the Depository. Neither the Corporation nor the Warrant Agent shall have any
responsibility or liability for any aspect of the records relating to beneficial
ownership interests in a Global Warrant Certificate or for maintaining,
supervising or reviewing any records relating to any such beneficial ownership
interest. As used herein, the term "Depository

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Participant" shall include any participant in the Depository's system and, for
purposes of this Agreement, shall also mean any participant in the book-entry
system of any successor Depository. As used herein, the term "Indirect
Participant" shall include any other bank, securities dealer, trust company or
other Person (as defined below) that clears or maintains a custodial
relationship with a Depository Participant, either directly or indirectly. As
used herein, the term "Person" shall include any individual, corporation,
partnership, joint venture, association, joint-stock company, trust,
unincorporated organization or government or any agency or political subdivision
thereof.

            (e)   The Corporation may from time to time select a new Person to
act as Depository and, if such selection is made, the Corporation shall promptly
give the Warrant Agent and the existing Depository notice to such effect
identifying the new Depository. As promptly as practicable thereafter, the
Depository shall deliver each Global Warrant Certificate then held by it to the
Warrant Agent, and the Warrant Agent shall register the transfer of such Global
Warrant Certificate to the new Depository as provided in Section 1.04.
Appropriate changes may be made in each Global Warrant Certificate, and in the
notice of exercise and the related notices delivered in connection with an
exercise or deemed exercise of Warrants to reflect the selection of the new
Depository.

            Section 1.02. Form; Denominations; Execution, Countersignature,
Delivery and Dating of Global Warrant Certificates. (a) At any time and from
time to time after the execution and delivery of this Agreement, the Corporation
may deliver one or more Global Warrant Certificates, each representing any
integral number of Warrants [not exceeding ________________ Warrants originally
issued,] executed by the Corporation as set forth in Section 1.02(b), to the
Warrant Agent for countersignature, together with a Corporation Order for the
countersignature and delivery of such Warrants, and the Warrant Agent shall
manually countersign and deliver such Warrants in accordance with such
Corporation Order. During such time as Warrants shall be represented by Global
Warrant Certificates, the Corporation may issue additional Warrants in
accordance with the terms of this Agreement either by issuing an additional
Global Warrant Certificate

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or by issuing a new Global Warrant Certificate in exchange for the existing
Global Warrant Certificate, provided that any such exchange shall conform to the
requirements set forth in Section 1.04(f).

            (b)   Each Global Warrant Certificate, whenever issued, shall be in
registered form substantially in the form of Exhibit A, with such appropriate
insertions, omissions, substitutions and other variations as are required or
permitted by this Agreement. Each Global Warrant Certificate shall be printed,
lithographed, typewritten, mimeographed or engraved on steel engraved borders or
otherwise reproduced in any other manner as may be approved by the officers
executing the same (such execution to be conclusive evidence of such approval)
and may have imprinted or otherwise reproduced thereon such letters, numbers or
other marks of identification or designation and such legends or endorsements as
the officers of the Corporation executing the same may approve (such execution
to be conclusive evidence of such approval) and that are not inconsistent with
the provisions of this Agreement, or as may be required to comply with any law
or with any rule or regulation made pursuant thereto, or with any rule or
regulation of any securities exchange on which the Warrants may be listed, or of
the Depository, or to conform to usage. Each Global Warrant Certificate shall be
signed on behalf of the Corporation by its Chairman of the Board, its Vice
Chairman, its President or one of its Vice Presidents, under its corporate seal
reproduced thereon and attested by its Secretary or one of its Assistant
Secretaries. The signature of any such officer on any Global Warrant Certificate
may be either manual or facsimile. Typographical and other minor errors or
defects in any such reproduction of the seal or any such signature shall not
affect the validity or enforceability of any Global Warrant Certificate that has
been duly countersigned and delivered by the Warrant Agent.

            (c)   No Global Warrant Certificate shall be entitled to any benefit
under this Agreement or be valid or obligatory for any purpose, and no Warrant
evidenced thereby shall be exercisable, unless such Global Warrant Certificate
has been countersigned by the Warrant Agent. Such signature by the Warrant Agent
upon any Global Warrant Certificate executed by the Corporation shall be
conclusive evidence, and the only evidence, that such Global Warrant

                                      -5-
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Certificate so countersigned has been duly issued hereunder.

            (d)   Any Global Warrant Certificate bearing the manual or facsimile
signatures of individuals who were at the time of such signature the proper
officers of the Corporation shall bind the Corporation, notwithstanding that
such individuals or any of them have ceased to hold such offices prior to the
countersignature and delivery of such Global Warrant Certificate or did not hold
such offices at the date of such Global Warrant Certificate.

            (e)   Each Global Warrant Certificate shall be dated the date of its
countersignature.

            Section 1.03. Definitive Warrant Certificates. (a) Any Definitive
Warrant Certificate issued in accordance with Section 1.01(c), whenever issued,
shall be in registered form substantially in the form of Exhibit A, with such
appropriate insertions, omissions, substitutions and other variations as are
required or permitted by this Agreement or necessary or desirable for individual
Definitive Warrant Certificates, provided that each such Definitive Warrant
Certificate shall have imprinted on the reverse thereof the Exercise Notice
substantially in the form of Exhibit B-2. Each Definitive Warrant Certificate
may represent any integral number of Warrants [not exceeding ________________
Warrants originally issued], shall be printed, lithographed, typewritten,
mimeographed or engraved on steel engraved borders or otherwise reproduced in
any other manner as may be approved by the officers executing the same (such
execution to be conclusive evidence of such approval), and may have imprinted or
otherwise reproduced thereon such letters, numbers or other marks of
identification or designation and such legends or endorsements as the officers
of the Corporation executing the same may approve (such execution to be
conclusive evidence of such approval) and that are not inconsistent with the
provisions of this Agreement, or as may be required to comply with any law or
with any rule or regulation made pursuant thereto, or with any rule or
regulation of any securities exchange on which the Warrants may be listed, or of
the Depository, or to conform to usage. Each Definitive Warrant Certificate
shall be signed on behalf of the Corporation upon the same conditions, in
substantially the same manner and with the same effect as

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set forth in Section 1.02 with respect to Global Warrant Certificates.

            (b)   Each Definitive Warrant Certificate, when so signed on behalf
of the Corporation, shall be delivered to the Warrant Agent together with a
Corporation Order for the countersignature and delivery of such Warrants, and
the Warrant Agent shall manually countersign and deliver such Warrants in
accordance with such Corporation Order upon the same conditions, in
substantially the same manner and with the same effect as set forth in Section
1.02 with respect to Global Warrant Certificates. Each Definitive Warrant
Certificate shall be dated the date of its countersignature.

            (c)   No Definitive Warrant Certificate shall be entitled to any
benefit under this Agreement or be valid or obligatory for any purpose, and no
Warrant evidenced thereby shall be exercisable, unless such Definitive Warrant
Certificate has been countersigned by the Warrant Agent. Such signature by the
Warrant Agent upon any Definitive Warrant Certificate executed by the
Corporation shall be conclusive evidence, and the only evidence, that such
Definitive Warrant Certificate so countersigned has been duly issued hereunder.

            (d)   Any Definitive Warrant Certificate bearing the manual or
facsimile signatures of individuals who were at the time of such signature the
proper officers of the Corporation shall bind the Corporation, notwithstanding
that such individuals or any of them have ceased to hold such offices prior to
the countersignature and delivery of such Definitive Warrant Certificate or did
not hold such offices at the date of such Definitive Warrant Certificate.

            (e)   Definitive Warrant Certificates delivered in exchange for a
Global Warrant Certificate shall be registered in such names and addresses
(including tax identification numbers) and in such denominations as shall be
requested in writing by the Depository or its nominee in whose name such Global
Warrant Certificate is registered, upon written certification to the Corporation
and the Warrant Agent, in form satisfactory to each of them, of the existing
beneficial ownership interests in such Global Warrant Certificate.

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            (f)   The Holder of any Warrant represented by a Definitive Warrant
Certificate shall be the Person in whose name such Definitive Warrant
Certificate is registered in the Warrant Register (as defined in Section 1.04)
at such time.

            Section 1.04. Maintenance of Warrant Register; Registration of
Transfers and Exchanges of Global Warrant Certificates. (a) The Corporation
shall cause to be kept at the Warrant Agent Office (as defined in Section
1.04(b)) a register (the "Warrant Register"), which may be maintained
electronically and in which, subject to such reasonable regulations as it may
prescribe, the Corporation shall provide for the registration and registration
of transfer, exchange, exercise and cancellation of Warrants. The Warrant Agent
is hereby appointed "Warrant Registrar" for the purpose of registering Warrant
Certificates and transfers and exchanges of Warrant Certificates as herein
provided.

            (b)   A Warrant Certificate may be transferred at the option of the
Holder thereof upon surrender of such Warrant Certificate at the office or
agency of the Warrant Agent maintained for the purpose of transferring,
exchanging, exercising and canceling the Warrants, which shall be south of
Chambers Street in the Borough of Manhattan, The City of New York (the "Warrant
Agent Office"), and which is, on the date of this Agreement,
_______________________, New York, New York, _____, Attention: [Corporate Trust
Department], or at the office of any successor Warrant Agent as provided in
Article IV. Upon any such registration of transfer, the Corporation shall
execute, and the Warrant Agent shall countersign and deliver, as provided in
Section 1.02 or 1.03, as the case may be, in the name of the designated
transferee a new Global Warrant Certificate or Definitive Warrant Certificate,
as the case may be, of like tenor, of any authorized denomination and
representing in the aggregate a like number of unexercised Warrants as evidenced
by such Warrant Certificate at the time of such registration of transfer, and
bearing a number not contemporaneously outstanding.

            (c)   A Warrant Certificate may be exchanged at the option of the
Holder thereof for other Global Warrant Certificates or Definitive Warrant
Certificates, as the

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case may be, of like tenor, of any authorized denomination and representing in
the aggregate a like number of unexercised Warrants, upon surrender of such
Warrant Certificate at the Warrant Agent Office. Whenever any Warrant
Certificate is so surrendered for exchange, the Corporation shall execute, and
the Warrant Agent shall countersign and deliver, as provided in Section 1.02 or
1.03, as the case may be, the Global Warrant Certificates or Definitive Warrant
Certificates, as the case may be, that the Holder of such exchanged Warrant
Certificate is entitled to receive and bearing a number not contemporaneously
outstanding.

            (d)   Any Warrant Certificate presented or surrendered for
registration of transfer or for exchange shall be duly endorsed or accompanied
by a written instrument or instruments of transfer in form satisfactory to the
Warrant Agent and the Corporation, duly signed by the registered Holder thereof
or by the duly appointed legal representative thereof or by a duly authorized
attorney, such signature to be guaranteed by a bank or trust company, by a
broker or dealer that is a member of the National Association of Securities
Dealers, Inc. or by a member of a national securities exchange.

            (e)   Except as otherwise provided herein or in a Global Warrant
Certificate, the Warrant Agent shall register the transfer of such Global
Warrant Certificate on the records of the Warrant Agent only to the Depository,
to a nominee of the Depository, to a successor Depository or to a nominee of the
successor Depository.

            (f)   A Global Warrant Certificate may be exchanged for a new Global
Warrant Certificate to reflect the issuance by the Corporation of additional
Warrants[; provided, however, that in no event shall the number of Warrants
represented by any Global Warrant Certificate exceed ___________________
originally issued]. To effect such an exchange, the Corporation shall deliver to
the Warrant Agent a new Global Warrant Certificate duly executed on behalf of
the Corporation as provided in Section 1.02, together with a Corporation Order
for the countersignature and delivery of such Warrants. The Warrant Agent shall
countersign such new Global Warrant Certificate as provided in Section 1.02 and
in accordance with such Corporation Order, and shall deliver such new

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Global Warrant Certificate to the Depository in exchange for, and upon receipt
of, the Global Warrant Certificate then held by the Depository. The Warrant
Agent shall cancel the Global Warrant Certificate delivered to it by the
Depository and return the canceled Global Warrant Certificate to the
Corporation.

            (g)   All Warrant Certificates issued upon any registration of
transfer or exchange of Global Warrant Certificates or Definitive Warrant
Certificates, as the case may be, shall be valid obligations of the Corporation,
evidencing the same obligations of the Corporation and entitled to the same
benefits under this Agreement, as the Warrant Certificates surrendered upon such
registration of transfer or exchange. The Warrant Agent shall not be required to
effect any exchange or transfer that would result in the issuance of a Warrant
Certificate evidencing a fraction of a Warrant or a number of full Warrants and
a fraction of a Warrant.

            (h)   No service charge shall be made for any registration of
transfer or exchange of Warrant Certificates, but the Corporation may require
payment of a sum sufficient to cover any stamp or other tax or other
governmental charge that may be imposed in connection with any such transfer or
exchange.

            Section 1.05. Mutilated, Destroyed, Lost and Stolen Warrant
Certificates. (a) If any mutilated Warrant Certificate is surrendered to the
Warrant Agent, the Corporation shall execute, and the Warrant Agent shall
countersign and deliver in exchange therefor, as provided in Section 1.02 or
1.03, as the case may be, a new Warrant Certificate of like tenor representing a
like number of unexercised Warrants and bearing a number not contemporaneously
outstanding.

            (b)   If there shall be delivered by a Holder of a Warrant
Certificate to the Corporation and the Warrant Agent (i) evidence to their
satisfaction of the destruction, loss or theft of any Warrant Certificate, (ii)
such security or indemnity as may be required by them to save each of them and
any agent of either of them harmless, and (iii) funds sufficient to cover any
cost or expense to the Corporation (including any fees charged by the Warrant
Agent) relating to the issuance of a new

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Warrant Certificate, then, in the absence of notice to the Corporation or the
Warrant Agent that such Warrant Certificate has been acquired by a bona fide
purchaser, the Corporation shall execute, and the Warrant Agent shall
countersign and deliver, as provided in Section 1.02 or 1.03, as the case may
be, in lieu of any such destroyed, lost or stolen Warrant Certificate, a new
Warrant Certificate of like tenor representing a like number of unexercised
Warrants and bearing a number not contemporaneously outstanding.

            (c)   If the Warrants evidenced by any such mutilated, destroyed,
lost or stolen Warrant Certificate have been exercised, or have been or are
about to be deemed to be exercised, the Corporation in its discretion may,
instead of issuing a new Warrant Certificate, treat the same as if it had
received written irrevocable notice of exercise in good form in respect thereof,
as provided herein.

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

            (e)   Every new Warrant Certificate issued pursuant to this Section
1.05 in lieu of any mutilated, destroyed, lost or stolen Warrant Certificate
shall constitute an original additional contractual obligation of the
Corporation, whether or not the mutilated, destroyed, lost or stolen Warrant
Certificate shall be at any time enforceable by anyone, and shall be entitled to
all the benefits of this Agreement equally and proportionately with any and all
other Warrant Certificates duly issued hereunder.

            (f)   The provisions of this Section 1.05 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 Warrant
Certificates.

            Section 1.06. Cancellation of Warrants. (a) If the Corporation shall
purchase or otherwise acquire

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Warrants represented by a Global Warrant Certificate, such Warrants may, at the
option of the Corporation and upon notification to the Warrant Agent, be
surrendered free through a Depository Participant for credit to the Warrant
Account (as defined in Section 2.01(b)) and if so credited, the Warrant Agent
shall promptly note the cancellation of such Warrants by notation on the records
of the Warrant Agent and on the Warrant Register.

            (b)   When all of the Warrants represented by any Global Warrant
Certificate have been exercised by the Owner thereof, automatically exercised or
otherwise canceled, and upon receipt of the same by the Warrant Agent, the
Warrant Agent shall promptly cancel such Global Warrant Certificate.

            (c)   The Corporation may at any time deliver to the Warrant Agent
for cancellation any Definitive Warrant Certificates previously countersigned
and delivered hereunder that the Corporation may have acquired in any manner
whatsoever, and the Warrant Agent shall promptly cancel all Definitive Warrant
Certificates so delivered.

            (d)   All Warrant Certificates surrendered for exercise,
registration of transfer or exchange or cancellation, if surrendered to any
Person other than the Warrant Agent, shall be delivered to the Warrant Agent,
and the Warrant Agent shall promptly cancel all such Warrant Certificates and
all other Warrant Certificates surrendered to it for exercise, registration of
transfer or exchange or cancellation.

            (e)   No Warrant Certificate shall be countersigned in lieu of or in
exchange for any Warrant Certificate canceled as provided in this Section 1.06
except as expressly permitted by this Agreement. All canceled Warrant
Certificates held by the Warrant Agent shall be destroyed by it unless by
written order the Corporation requests their return to it.

                                   ARTICLE II

               [EXERCISE PRICE,] DURATION AND EXERCISE OF WARRANTS

            Section 2.01. Duration of Warrants; Method of Exercise; Minimum [and
Maximum] Exercise Amounts; Notice of

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<PAGE>
Exercise. (a) Subject to the limitations described herein, each Warrant may be
exercised in whole but not in part on any New York Business Day (as defined in
Section 2.01(f)) from [its date of issuance (specify other date if applicable)]
until [3:00 P.M.], New York City time, on the earlie[st] of (i) [______________
(specify date upon which right to exercise Warrants expires)] or, if such date
is not a New York Business Day, on the next succeeding New York Business Day
(the "Expiration Date"), [or] (ii) the date of automatic exercise as provided in
Section 2.03 [or (iii) the date of cancellation as provided in Section 2.04][;
provided that the Corporation may temporarily suspend the right of the Holders
to exercise their Warrants pursuant to the provisions of Section 2.08]. [No
exercise price shall be payable by any Holder or Owner in connection with the
exercise of any Warrant.] [The exercise price for each Warrant shall be $_____
and shall be payable [in U.S. dollars (specify other currency if applicable)]
(the "Exercise Price").]

            (b)   Except in the case of automatic exercise, each Warrant may be
exercised by:

            (i)   in the case of any Warrant represented by a Global Warrant
      Certificate (each, a "Book-Entry Warrant"), (A) transfer of such Warrant
      on the records of the Depository free to the Warrant Agent's Depository
      Participant account (entitled ____________________), or such other account
      of the Warrant Agent at the Depository as the Warrant Agent shall specify
      (the "Warrant Account"), [and] (B) delivery to the Warrant Agent as
      provided in Section 2.01(d)(i)(C) of written notice (an "Exercise Notice")
      duly completed and executed by a Depository Participant acting on behalf
      of the Owner of such Warrant [and (C) payment of the Exercise Price [in
      U.S. dollars (specify other currency if applicable)] [in cash or by
      cashier's check or official bank check in New York Clearing House funds]
      [by bank wire transfer in immediately available funds] payable to the
      account of the Corporation]; and

            (ii)  in the case of Warrants represented by a Definitive Warrant
      Certificate (each, a "Certificated Warrant"), (A) surrender of such
      Definitive Warrant Certificate to the Warrant Agent at the Warrant Agent
      Office, [and] (B) delivery to the Warrant Agent

                                      -13-
<PAGE>
      as provided in Section 2.01(d)(ii)(C) of an Exercise Notice duly completed
      and executed by the Holder of such Warrant [and (C) payment of the
      Exercise Price [in U.S. dollars (specify other currency if applicable)]
      [in cash or by cashier's check or official bank check in New York Clearing
      House funds] [by bank wire transfer in immediately available funds]
      payable to the account of the Corporation];

provided, however, that each Exercise Notice is subject to rejection by the
Warrant Agent as provided herein.

            (c)   Not fewer than [specify minimum exercise amount] [nor more
than [specify maximum exercise amount]] Warrants may be exercised by or on
behalf of any one Owner or, in the case of Certificated Warrants, any one Holder
at any one time, except that no such minimum [or maximum] exercise amount shall
apply in the case of (i) the automatic exercise of any Warrants, or (ii) the
exercise of any Warrants on the Expiration Date.

            (d)   An Exercise Notice [may be conditioned as set forth in Section
2.02(b), but] shall [otherwise] be unconditional. Each Exercise Notice shall be
irrevocable and:

            (i)   in the case of any Book-Entry Warrant, shall (A) be in the
      form of Exhibit B-1 hereto, [(B) shall include a certification by the
      Depository Participant submitting such Exercise Notice that the Owners
      affected by such Exercise Notice are not Index Country Residents (as
      defined in Section 2.01(f))] and (C) shall be sent to the Warrant Agent in
      writing at its address as set forth in such form of Exercise Notice or at
      such other address as the Warrant Agent may specify from time to time by
      notice given in accordance with Section 8.05; and

            (ii)  in the case of any Certificated Warrant, shall (A) be in the
      form of Exhibit B-2 hereto and shall, unless otherwise agreed by the
      Corporation and the Warrant Agent, be set forth on the reverse of the
      Definitive Warrant Certificate representing such Certificated Warrant,
      [(B) shall include a certification by the Holder of such Certificated

                                      -14-
<PAGE>
      Warrants that such Holder is not an Index Country Resident] and (C) shall
      be sent to the Warrant Agent in writing at its address as set forth in
      such form of Exercise Notice or at such other address as the Warrant Agent
      may specify from time to time by notice given in accordance with Section
      8.05.

            (e)   Except as provided in Section 2.02(c), the Warrant Agent and
the Corporation shall be entitled to rely conclusively on any Exercise Notice
received by the Warrant Agent with no duty of inquiry by either of them.

            (f)   As used in this Agreement, "New York Business Day" means any
day other than a Saturday or Sunday or a day on which the [New York Stock
Exchange or American Stock Exchange (list any other relevant securities
exchanges)] is not open for securities trading or banking institutions generally
in The City of New York are authorized or required by law or executive order to
close; "Index Country Business Day" means any day other than (i) a Saturday or
Sunday or a day on which banking institutions generally in [(specify name of
Index country)] are authorized or required by law or executive order to close or
(ii) a day on which the [(list names of relevant exchanges)] are not open for
business[; and "Index Country Resident" means a resident of, or any corporation
or other Person organized under the laws of [(specify name of Index country)],
its territories, its possessions or other areas subject to its jurisdiction].

            Section 2.02. Exercise of Warrants. (a) Except in the case of
automatic exercise as provided in Section 2.03 [or cancellation as provided in
Section 2.04] and subject to Section 2.02(c)([ii]) [and 2.02(f)], the exercise
date (the "Exercise Date") for a Warrant shall be (i) the New York Business Day
on which the Warrant Agent receives delivery of such Warrant to the Warrant
Account, in the case of Book-Entry Warrants, or of the Definitive Warrant
Certificate representing such Warrant at the Warrant Agent Office, in the case
of Certificated Warrants, [and] an Exercise Notice relating to such Warrant in
good order [and payment of the Exercise Price in the manner specified in Section
2.01(b)], if such receipt occurs at or prior to [3:00] P.M., New York City time,
on such New York Business Day, and (ii) otherwise the New York Business Day next
succeeding the day on which the Warrant Agent receives

                                      -15-
<PAGE>
such Warrant[, the Exercise Price] and such Exercise Notice, which next
succeeding New York Business Day shall be the day on which such Warrant[,
Exercise Price] and Exercise Notice shall be deemed to have been received. If
any Exercise Notice[, the related Exercise Price] or the Warrants to which such
Exercise Notice relates are received after [3:00] P.M., New York City time, on
the Expiration Date, such Exercise Notice shall be void and of no effect and
shall be deemed not to have been delivered. Except in the case of automatic
exercise as provided in Section 2.03, the "Valuation Date" for a Warrant shall
be the first Index Country Business Day next succeeding the Exercise Date of
such Warrant. [The "Designated Exercise Date" for a Warrant shall be the date
that, but for the provisions of Section 2.02(f), would be the Exercise Date for
such Warrant in accordance with this Section 2.02(a).]

            [(b)  Notwithstanding anything in this Agreement to the contrary, if
a Depository Participant, in the case of Book-Entry Warrants, or a Holder, in
the case of Certificated Warrants, has specified in its Exercise Notice that
such Exercise Notice is conditional (a "Conditional Exercise Notice"), then such
Conditional Exercise Notice shall be void and of no effect, and shall be
disregarded for all purposes of this Agreement, if [Describe the terms upon
which the Exercise Notice may be conditional, which may be as follows: the Spot
Index (as defined in Section 2.02(g)) on the day that, but for the provisions of
this Section 2.02(b), would be the Valuation Date for such Warrants is more than
__________ [above] [below] the Spot Index on the [Designated] Exercise Date of
such Warrants (or, if the [Designated] Exercise Date is not an Index Country
Business Day, on the immediately preceding Index Country Business Day) (the
"Reference Value").]

            (c)   Following receipt of proper delivery of any Warrant[, the
Exercise Price] and the Exercise Notice related to such Warrant in accordance
with Section 2.01(b), the Warrant Agent shall:

            [(i)  deposit all funds received by it in payment of the Exercise
      Price of such Warrant to the account of the Corporation maintained with it
      for such purpose (unless otherwise instructed in writing by the
      Corporation), and advise the Corporation by telephone and in writing, by
      facsimile transmission or

                                      -16-
<PAGE>
      otherwise, at the end of each day on which any such payment is received of
      the amount so deposited to its account;]

            (ii)(A) in the case of a Book-Entry Warrant, promptly determine
      whether such Exercise Notice has been duly completed and is in proper form
      and verify that the Person that executed such Exercise Notice is listed as
      a Depository Participant in the most recent published edition of the
      Depository's Eligible Corporate Securities Book (or the comparable
      publication of any successor Depository) and, if such Person is not listed
      therein, make reasonable efforts to obtain verbal verification from the
      Depository's Planning Department (telephone number 212-709-1000) (or the
      comparable department of a successor Depository) that such Person is a
      Depository Participant; and (B) in the case of a Certificated Warrant,
      promptly determine whether such Exercise Notice has been duly completed
      and is in proper form and whether the Definitive Warrant Certificate
      representing such Warrant is in proper form;

            (iii)(A) in the case of a Book-Entry Warrant, if the Warrant Agent
      determines that such Exercise Notice has not been duly completed or is not
      in proper form, or is unable through the procedures described in clause
      ([ii])(A) above to verify that the Person that submitted such Exercise
      Notice is a Depository Participant, then the Warrant Agent shall reject
      such Exercise Notice and shall send to the Depository Participant that
      submitted such Exercise Notice a notice of rejection substantially in the
      form of Exhibit C hereto (a "Rejection Notice") and redeliver the Warrants
      to which such rejected Exercise Notice relates free through the facilities
      of the Depository to the account from which they were transferred; and (B)
      in the case of a Certificated Warrant, if the Warrant Agent determines
      that such Exercise Notice has not been duly completed or is not in proper
      form, or that the Definitive Warrant Certificate representing such Warrant
      is not in proper form, then the Warrant Agent shall reject such Exercise
      Notice and shall send a Rejection Notice to the Holder of such Warrants
      and return such Definitive Warrant Certificate to such

                                      -17-
<PAGE>
      Holder by first class mail at the expense of the Corporation;

            (iv)  by [5:00 P.M.], New York City time, on the New York Business
      Day on which such Exercise Notice is received (or deemed to have been
      received), notify the Corporation (and such other parties (not to exceed
      two) as the Corporation shall designate in writing) of (A) the total
      number of Warrants in respect of which Exercise Notices were received (or
      deemed to have been received) at or prior to [3:00 P.M.], New York City
      time, on such date [and] (B) the number of such Exercise Notices that were
      rejected by the Warrant Agent pursuant to clause ([iii]) above and the
      aggregate number of Warrants to which such rejected Exercise Notices
      relate[, and (C) the number of such Exercise Notices that were Conditional
      Exercise Notices and the aggregate number of Warrants to which such
      Conditional Exercise Notices relate];

            [(v)  if any of such Exercise Notices are Conditional Exercise
      Notices, by [5:00 P.M.], New York City time, on the Valuation Date for
      such Warrants (or, if such Valuation Date is not a New York Business Day,
      on the next succeeding New York Business Day), (A) determine the Reference
      Value for such Warrants and the Spot Index for the date that, but for the
      provisions of Section 2.02(b), would be the Valuation Date of such
      Warrants; (B) determine whether any Conditional Exercise Notices have
      become void pursuant to such Section 2.02(b); and (C) if so, promptly
      notify the Corporation (and such other parties (not to exceed two) as the
      Corporation shall designate in writing) and send a Rejection Notice to the
      appropriate Depository Participant or Holder, as the case may be, and (x)
      in the case of Book-Entry Warrants, redeliver such Warrants free through
      the facilities of the Depository to the account from which they were
      transferred or (y) in the case of Certificated Warrants, return such
      Warrants to such Holder by first class mail at the expense of the
      Corporation.]

            (vi)  by [5:00 P.M.], New York City time, on the Valuation Date for
      such Warrants (or, if such Valuation Date is not a New York Business Day,
      on the

                                      -18-
<PAGE>
      next succeeding New York Business Day), determine the aggregate number of
      Warrants covered by Exercise Notices that have not [become void pursuant
      to Section 2.02(b) or] been rejected pursuant to clause ([iii]) above (the
      "[Exercised] [Tendered] Warrants");

            (vii) by [5:00 P.M.], New York City time, on the Valuation Date for
      the Tendered Warrants (or, if such Valuation Date is not a New York
      Business Day, on the next succeeding New York Business Day), determine
      pursuant to Section 2.02(f) the number of such Tendered Warrants that
      shall not be Delayed Exercise Warrants (such Tendered Warrants, the
      "Exercised Warrants");]

            (viii) by [5:00 P.M.], New York City time, on the Valuation Date for
      the Exercised Warrants (or, if such Valuation Date is not a New York
      Business Day, on the next succeeding New York Business Day), (A) determine
      the Cash Settlement Value of the Exercised Warrants, (B) notify the
      Corporation (and such other parties (not to exceed two) as the Corporation
      shall designate in writing) of the aggregate Cash Settlement Value with
      respect to such Exercised Warrants, and (C) send notice of confirmation of
      exercise in substantially the form of Exhibit D hereto to the appropriate
      Depository Participant or Holder, as the case may be; and

            (ix)  promptly deliver a copy of each such Exercise Notice to the
      Corporation and advise the Corporation of such other matters relating to
      any of the Warrants covered thereby, whether or not they constitute
      [Tendered Warrants or] Exercised Warrants, as the Corporation shall
      reasonably request.

            (d)   At or before [3:00 P.M.], New York City time, on the [fifth]
New York Business Day following the Valuation Date for any Exercised Warrants
(or, if such Valuation Date is not a New York Business Day, on the [sixth] New
York Business Day after such Valuation Date) (such date, with respect to such
Exercised Warrants, the "Settlement Date"), the Corporation shall make available
to the Warrant Agent funds in an amount equal to, and for the payment of, the
aggregate Cash Settlement Value of such Exercised Warrants. On the New York
Business Day on which

                                      -19-
<PAGE>
the Corporation has made adequate funds available to the Warrant Agent at or
prior to [3:00 P.M.], New York City time, the Warrant Agent shall make payment
available (i) if the Exercised Warrants are Book-Entry Warrants, in the form of
a wire transfer to the appropriate Depository Participant after [3:00 P.M.], New
York City time, but prior to the close of business, on such day, such payment to
be in the amount of the aggregate Cash Settlement Value of the Exercised
Warrants exercised by such Depository Participant, and (ii) if the Exercised
Warrants are Certificated Warrants, in the form of one or more cashier's checks
or official bank checks to each appropriate Holder after [3:00 P.M.], New York
City time, but prior to the close of business, on such day, such payment to be
in the amount of the Cash Settlement Value of the Exercised Warrants exercised
by such Holder. In the case of payments by the Warrant Agent to a Depository
Participant, the Warrant Agent shall have no responsibility for the crediting by
such Depository Participant of the Cash Settlement Value of such Warrants to the
appropriate Owners.

            (e)   (i) The Warrant Agent shall cause its records, which may be
kept electronically, to be marked to reflect the reduction in the number of
Warrants evidenced by each Global Warrant Certificate by the number of such
Warrants for which payment has been made available as provided in Section
2.02(d) promptly after such payment has been made available. In the absence of
manifest error, the Warrant Agent's records shall be conclusive evidence as to
such matters.

            (ii)  If any Definitive Warrant Certificate shall be surrendered to
the Warrant Agent for exercise of fewer than all the Warrants represented
thereby, the Corporation shall execute, and the Warrant Agent shall countersign,
as provided in Section 1.02 or 1.03, as the case may be, and deliver to the
Holder of such Warrants by first class mail at the expense of the Corporation a
new Definitive Warrant Certificate of like tenor representing all Warrants
remaining unexercised after such exercise and bearing a number not
contemporaneously outstanding.

            [(f)  The Corporation may, at its sole option, elect to limit the
aggregate number of Warrants for which any Designated Exercise Date shall be the
Exercise Date to

                                      -20-
<PAGE>
a number not less than ________________ (the "Maximum Exercisable Number").

            (i)   The Corporation may, at its sole option, notify the Warrant
      Agent in writing (including by facsimile transmission) not later than
      [3:00 P.M.], New York City time, on the Valuation Date with respect to any
      Tendered Warrants (or, if such Valuation Date is not a New York Business
      Day, on the next succeeding New York Business Day), that the Corporation
      has elected to exercise its option under this Section 2.02(f) to limit the
      number of such Tendered Warrants for which the Exercise Date to which such
      Valuation Date relates shall be the Designated Exercise Date for such
      Warrants to a number (the "Elected Maximum Number") not smaller than the
      Maximum Exercisable Number. If the Warrant Agent shall not have received
      such notice by such time, none of the following provisions in this Section
      2.02(f) shall apply to such Tendered Warrants, such Designated Exercise
      Date shall be the Exercise Date for such Tendered Warrants, and all of
      such Tendered Warrants shall be deemed to be "Exercised Warrants" for
      purposes of this Agreement.

            (ii)  If the Warrant Agent shall have received the notice
      contemplated by clause (i) above by the time specified in such clause (i),
      then prior to [5:00 P.M.], New York City time, on such Valuation Date (or,
      if such Valuation Date is not a New York Business Day, on the next
      succeeding New York Business Day), the Warrant Agent shall select by lot
      from all such Tendered Warrants, subject to clause (iii) below, Tendered
      Warrants for which the Exercise Date shall be such Designated Exercise
      Date in an aggregate number equal to the Elected Maximum Number; provided
      that if, as a result of such selection, any Owner or Holder, as the case
      may be, would be deemed to have exercised less than [(specify minimum
      exercise amount)] Warrants, then the Warrant Agent shall first select
      additional Tendered Warrants of such Owners or Holders so that no such
      Owner or Holder shall be deemed to have exercised fewer than [(specify
      minimum exercise amount)] Warrants. Only the Tendered Warrants so selected
      shall be deemed to be "Exercised Warrants" for purposes of Section
      2.02(c). The Tendered Warrants not so selected shall be referred to herein

                                      -21-
<PAGE>
      as "Delayed Exercise Warrants" and shall be subject to exercise as
      provided in clause (iii) below.

            (iii) For purposes of this Section 2.02, each Delayed Exercise
      Warrant shall be deemed to have a new Designated Exercise Date on the New
      York Business Day next succeeding its original Designated Exercise Date,
      and this Section 2.02 shall apply to such Delayed Exercise Warrants as if
      one or more Exercise Notices with respect to the Delayed Exercise Warrants
      had been received by the Warrant Agent prior to [3:00 P.M.], New York City
      time, on such New York Business Day, provided that (x) any Delayed
      Exercise Warrant with respect to which any such deemed Designated Exercise
      Date is on or after the earlier of the Expiration Date and the Delisting
      Date shall be subject to automatic exercise as provided in Section 2.03[,
      and (y) the Reference Value for any Delayed Exercise Warrant covered by a
      Conditional Exercise Notice shall in any event be determined by reference
      to the original Designated Exercise Date therefor (or, if such date is not
      an Index Country Business Day, on the immediately preceding Index Country
      Business Day)]; provided, however, that, other than in the case of
      automatic exercise [or cancellation], if the aggregate number of such
      Delayed Exercise Warrants, together with any additional Tendered Warrants
      for which the Designated Exercise Date is such New York Business Day shall
      again exceed the Maximum Exercisable Number, the provisions of this
      Section 2.02(f) shall apply, mutatis mutandis, to the exercise of such
      Delayed Exercise Warrants and such additional Tendered Warrants, provided
      that such Delayed Exercise Warrants shall be given priority over such
      additional Tendered Warrants in the selection pursuant to clause (ii)
      above, and among such Delayed Exercise Warrants, priority in such
      selections shall be given to Warrants in the order of their original
      Designated Exercise Dates, with Warrants having the same original
      Designated Exercise Date being selected by lot as described in clause (ii)
      above.

            (iv)  In connection with any issuance by the Corporation of
      additional Warrants under this Agreement, the Corporation shall have the
      right, but

                                      -22-
<PAGE>
      shall not be obligated, to increase the Maximum Exercisable Number.]

            (g)   For purposes of this Agreement:

            The "Cash Settlement Value" of any Warrant that is exercised
      (whether exercised automatically or by Exercise Notice) shall mean [_____
      (specify fraction)] of the U.S. dollar equivalent (rounded to the nearest
      dollar) of the amount, if any, by which [(i) the Strike Index (as defined
      below) exceeds (ii) the Spot Index on the Valuation Date with respect to
      such Exercised Warrant] [(i) the Spot Index on the Valuation Date with
      respect to such Exercised Warrant exceeds (ii) the Strike Index (as
      defined below)]; provided that if such amount is less than zero, the Cash
      Settlement Value shall be zero.

            The "Strike Index" of a Warrant shall mean [Insert amount or method
      for determining amount].

            The "Spot Index" on any date shall mean [Insert method for
      determining amount].

            The exchange rate (or manner of calculating such rate) for
      conversion of the Cash Settlement Value, [the Cancellation Amount,] the
      Strike Index, the Spot Index and/or the value of Underlying Securities, as
      applicable, into U.S. dollars shall be [(specify such rate or manner of
      calculating such rate)] and shall be determined by the Warrant Agent.

            "U.S. dollars", "U.S.$" or "$" are references to the currency of the
      United States of America.

            "[Index currency]" or "[_______________]" are references to the
      currency of [(specify name of Index country)].

            (h)   Any notice to be given to the Corporation by the Warrant Agent
pursuant to this Section 2.02 or Section 2.03 shall be by telephone (promptly
confirmed in writing) or telecopy (receipt to be promptly confirmed by
telephone).

                                      -23-
<PAGE>
            Section 2.03. Automatic Exercise of Warrants. (a) [Unless previously
canceled pursuant to Section 2.04,] all Warrants with respect to which

            (i)   there has been no proper delivery of Warrants to the Warrant
      Account, in the case of Book-Entry Warrants, or of Definitive Warrant
      Certificates to the Warrant Agent Office, in the case of Certificated
      Warrants[, or no delivery of the Exercise Price as provided in Section
      2.01(b)] or no valid Exercise Notice has been received by the Warrant
      Agent at or prior to [3:00 P.M.], New York City time, on the earlier to
      occur of (A) the Expiration Date for such Warrants and (B) the last New
      York Business Day prior to the effective date on which the Warrants are
      delisted from, or permanently suspended from trading on, the __________
      Stock Exchange without being accepted for listing on or prior to such New
      York Business Day on another United States national securities exchange
      (such New York Business Day, the "Delisting Date"),

            (ii)  the Exercise Date has been postponed pursuant to Section
      2.02(f) to a date on or after the earlier of the Expiration Date or the
      Delisting Date,

            [or (iii) [list other events causing automatic exercise of Warrants,
      if applicable]]

will be automatically exercised on such Expiration Date or Delisting Date [or on
the date on which (specify other events leading to automatic exercise)] (any
such date, a "Deemed Exercise Date") without any requirement of notice of
exercise to the Warrant Agent. On the Deemed Exercise Date, all the Warrants
will be canceled and will represent only a right to receive the Cash Settlement
Value upon satisfaction of the requirements set forth in Section 2.03(b). The
Valuation Date for such Warrants shall be the first Index Country Business Day
next succeeding such Deemed Exercise Date.

            (b)   On the Valuation Date for the Warrants to be automatically
exercised in accordance with Section 2.03(a) (or, if such Valuation Date is not
a New York Business Day, on the next succeeding New York Business Day), the
Warrant Agent shall (i) determine the Cash Settlement Value of such

                                      -24-
<PAGE>
Warrants; (ii) by [5:00 P.M.], New York City time, on such Valuation Date (or,
if such Valuation Date is not a New York Business Day, on the next succeeding
New York Business Day) notify the Corporation (and such other parties (not to
exceed two) as the Corporation shall designate in writing) of the Cash
Settlement Value of such Warrants; and (iii) advise the Corporation of such
other matters relating to the automatically exercised Warrants as the
Corporation shall reasonably request.

            (c)   At or before [3:00 P.M.], New York City time, on the [eighth]
New York Business Day following the Valuation Date for any Warrants
automatically exercised in accordance with Section 2.03(a) (or, if such
Valuation Date is not a New York Business Day, on the [ninth] New York Business
Day after such Valuation Date) (such date, with respect to such Warrants, the
"Settlement Date"), the Corporation shall make available to the Warrant Agent
funds in an amount equal to, and for the payment of, [(y)] the aggregate Cash
Settlement Value of such automatically exercised Warrants [minus (y) the
aggregate Exercise Price with respect to such Warrants, provided that if such
amount is less than zero, no such funds shall be made available]. On the New
York Business Day on which the Corporation has made adequate funds available to
the Warrant Agent at or prior to [3:00 P.M.], New York City time, the Warrant
Agent shall make payment available (i) if the automatically exercised Warrants
are Book-Entry Warrants, in the form of a wire transfer to the appropriate
Depository Participant after [3:00 P.M.], New York City time, but prior to the
close of business, on such day, such payment to be in the amount of [(x)] the
aggregate Cash Settlement Value of the Warrants held at the time of automatic
exercise by such Depository Participant [minus (y) the aggregate Exercise Price
with respect to such Warrants, provided that if such amount is less than zero,
then no such payment shall be made], and (ii) if the automatically exercised
Warrants are Certificated Warrants, in the form of one or more cashier's checks
or official bank checks to each appropriate Holder after [3:00 P.M.], New York
City time, but prior to the close of business, on such day, such payment to be
in the amount of [(x)] the Cash Settlement Value of the Warrants registered in
the name of such Holder on the date of automatic exercise [minus (y) the
aggregate Exercise Price with respect to such Warrants, provided that if such
amount is less than zero, then no such payment shall be made];

                                      -25-
<PAGE>
provided, however, that the Warrant Agent shall withhold any such payment in
respect of any Warrant until the conditions set forth in Section 2.03(d) have
been satisfied with respect to such Warrant. In the case of payments by the
Warrant Agent to a Depository Participant, the Warrant Agent shall have no
responsibility for the crediting by such Depository Participant of the Cash
Settlement Value of such Warrants to the appropriate Owners.

            (d)   The Warrant Agent shall withhold payment of the Cash
Settlement Value with respect to any automatically exercised Warrant until:

            (i)   if such Warrant is a Book-Entry Warrant, [(A)] such Warrant is
      delivered on the records of the Depository free to the Warrant Account
      [and (B) the Warrant Agent receives at the Warrant Agent Office a written
      certification substantially in the form of Exhibit E-1 hereto, dated no
      earlier than the Deemed Exercise Date, executed by a Depository
      Participant acting on behalf of the Owner of such Warrant, to the effect
      that such Owner is not an Index Country Resident]; and

            (ii)  if such Warrant is a Certificated Warrant, [(A)] the
      Definitive Warrant Certificate representing such Warrant is surrendered to
      the Warrant Agent at the Warrant Agent Office, [and (B) the Warrant Agent
      receives at the Warrant Agent Office a certification in the form of
      Exhibit E-2 hereto, dated no earlier than the Deemed Expiration Date, to
      the effect that the Holder of such Definitive Warrant Certificate is not
      an Index Country Resident].

            (e)   When payment has been made in respect of all Warrants
represented by a Warrant Certificate, the Warrant Agent shall, promptly upon
receipt of such Warrant Certificate, cancel such Warrant Certificate and deliver
it to the Corporation.

            [Section 2.04. Cancellation of Warrants. (a) [insert conditions and
effects of cancellation, if applicable].]

                                      -26-
<PAGE>
            (b)   [The "Cancellation Amount" of a Warrant shall mean [Insert
amount or method for determining amount].]

            Section 2.05. Discontinuance or Modification of Index. (a) If the
Index is not calculated and announced by [name of Index publisher] (the "Index
Publisher") on any Valuation Date but is calculated and publicly announced by
another Person not affiliated with the Corporation and acceptable to the
Corporation (the "Third Party"), the applicable Cash Settlement Value [or
Cancellation Amount, as the case may be,] shall be calculated by reference to
the value of the closing quotation for the Index so calculated and announced by
the Third Party.

            (b)   If, prior to any Valuation Date, the Index Publisher or the
Third Party shall make a material change in the formula for or the method of
calculating the Index, the Corporation shall promptly appoint an investment or
commercial bank of international standing that is not an affiliate of the
Corporation (an "Independent Expert") who shall make such calculations as may be
required to determine the applicable Cash Settlement Value [or Cancellation
Amount, as the case may be,] using the formula and method of calculating the
Index as in effect prior to such change or modification.

            (c)   If, on any Valuation Date, neither the Index Publisher nor any
Third Party is calculating and disseminating the Index and neither is providing
any successor index, the Corporation shall promptly appoint an Independent
Expert who shall make such calculations as it determines may be required to
determine the applicable Cash Settlement Value [or Cancellation Amount, as the
case may be,] using the formula and method of calculating the Index as in effect
on the date the Index was last so calculated.

            (d)   If any of the events referred to in Sections 2.05(a) through
(c) shall occur, the Corporation shall promptly make available information
regarding the composition, method of calculation and current level of the Index
or successor index upon written request to the Corporation's offices at 299 Park
Avenue, New York, New York 10017, Attention: [Robert Dinerstein]. In addition,
the Corporation shall undertake reasonable efforts to ensure that such
information is publicly available. If the

                                      -27-
<PAGE>
Index Publisher shall elect to suspend or discontinue calculating or announcing
the Index, the Corporation shall so notify Holders by giving notice to the
Holders as their names and addresses appear in the Warrant Register.

            Section 2.06. Designation of Agent for Receipt of Notice. The
Corporation may from time to time designate in writing to the Warrant Agent a
single designee for receipt of all notices required to be given by the Warrant
Agent to the Corporation pursuant to this Article II and all such notices
thereafter shall be given in the manner herein provided by the Warrant Agent to
such designee and each such notice shall be as effective as if given directly to
the Corporation.

            [Section 2.07. Extraordinary Events. [(Specify conditions and
effects of extraordinary events, if applicable)].]

            [Section 2.08. Temporary Suspension of the Right to Exercise the
Warrants. [(Specify conditions and method of temporary suspension of right to
exercise, if applicable)].]

                                  ARTICLE III

                          OTHER PROVISIONS RELATING TO
                                RIGHTS OF HOLDERS

            Section 3.01. Treatment of Holders. (a) The Corporation, the Warrant
Agent and any agent of the Corporation or the Warrant Agent may deem and treat
the Person in whose name each Global Warrant Certificate shall be registered in
the records of the Warrant Agent as the absolute Holder of all right, title and
interest in such Global Warrant Certificate (notwithstanding any notation of
ownership or other writing thereon) for all purposes hereunder and as the Person
entitled to exercise the rights represented by the Warrants evidenced thereby,
whether or not such Warrants shall be exercised or deemed to be exercised, and
neither the Corporation nor the Warrant Agent, nor any agent of the Corporation
or the Warrant Agent shall be affected by any notice to the contrary, except
that the Warrant Agent and the Corporation shall be entitled to rely on and act
pursuant to instructions of

                                      -28-
<PAGE>
Depository Participants as contemplated by Article II of this Agreement.

            (b)   Prior to due presentment of a Definitive Warrant Certificate
for registration of transfer, the Corporation, the Warrant Agent and any agent
of the Corporation or the Warrant Agent may treat the Person in whose name such
Definitive Warrant Certificate is registered as the absolute Holder of all
right, title and interest in such Definitive Warrant Certificate
(notwithstanding any notation of ownership or other writing thereon) for all
purposes hereunder and as the Person entitled to exercise the rights represented
by the Warrants evidenced thereby, whether or not such Warrants shall be
exercised or deemed to be exercised, and neither the Corporation, the Warrant
Agent nor any agent of the Corporation or the Warrant Agent shall be affected by
notice to the contrary.

            Section 3.02. Holder or Owner of Warrant May Enforce Rights.
Notwithstanding any other provision of this Agreement, any Owner, in the case of
Book-Entry Warrants, and any Holder, in the case of Certificated Warrants,
without the consent of the Warrant Agent or the Owner or Holder of any other
Warrant, may, in and for such Owner's or Holder's own behalf, and for such
Owner's or Holder's own benefit, enforce, and may institute and maintain any
suit, action or proceeding against the Corporation suitable to enforce, or
otherwise in respect of, such Owner's or Holder's right to exercise, and to
receive payment for, such Owner's or Holder's Warrants as provided in such
Warrants and in this Agreement.

                                   ARTICLE IV

                          CONCERNING THE WARRANT AGENT

            Section 4.01. Warrant Agent. The Corporation hereby appoints [name
of Warrant Agent] as the Warrant Agent of the Corporation in respect of the
Warrants upon the terms and subject to the conditions set forth herein and in
the Warrants, and [name of Warrant Agent] hereby accepts such appointment. The
Warrant Agent shall have the powers and authority granted to and conferred upon
it herein and in the Warrants and such further powers and authority acceptable
to it to act on behalf of the

                                      -29-
<PAGE>
Corporation as the Corporation may hereafter grant to or confer upon it. All of
the terms and provisions with respect to such powers and authority contained in
the Warrants are subject to and governed by the terms and provisions hereof.

            Section 4.02. Certain Duties of the Warrant Agent. (a) Except during
the continuation of a default in the performance by the Corporation of its
obligations in respect of the Warrants, the Warrant Agent undertakes to perform
such duties and only such duties as are specifically set forth in this
Agreement, and no implied covenants or obligations shall be read into this
Agreement against the Warrant Agent.

            (b)   No provision of this Agreement shall require the Warrant Agent
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.

            Section 4.03. Conditions of Warrant Agent's Obligations. The Warrant
Agent accepts its obligations set forth herein upon and subject to the terms and
conditions hereof and of the Warrants, including the following, to all of which
the Corporation agrees and to all of which the rights hereunder of the Owners
and Holders from time to time of the Warrants shall be subject:

            (a)   The Corporation agrees promptly to pay the Warrant Agent the
      compensation to be agreed upon with the Corporation for all services
      rendered by the Warrant Agent and to reimburse the Warrant Agent for its
      reasonable out-of-pocket expenses, disbursements and advances (including
      reasonable attorneys' fees and expenses and reasonable compensation,
      expenses and disbursements of its agents) incurred by the Warrant Agent
      without negligence, bad faith or breach of this Agreement on its part in
      connection with the services rendered by it hereunder. The Corporation
      also agrees to indemnify the Warrant Agent for, and to hold it harmless
      against, any loss, liability or expense (including reasonable attorneys'
      fees and expenses)

                                      -30-
<PAGE>
      incurred without negligence, bad faith or breach of this Agreement on the
      part of the Warrant Agent, arising out of or in connection with its acting
      as such Warrant Agent hereunder or with respect to the Warrants, including
      the reasonable costs and expenses of defending itself against any claim or
      liability in connection with the exercise or performance of any of its
      powers or duties hereunder. The obligations of the Corporation under this
      subsection (a) shall survive the exercise of the Warrants and the
      resignation or removal of the Warrant Agent.

            (b)   The Warrant Agent shall be protected and shall incur no
      liability for or in respect of any action taken or omitted or thing
      suffered by it in reliance upon any Warrant, resolution, opinion, report,
      request, notice, direction, consent, certificate, affidavit, statement or
      other paper or document reasonably believed by it to be genuine and to
      have been presented or signed by the proper parties, provided that any
      request or direction of the Corporation shall be sufficiently evidenced by
      a Corporation Order delivered to the Warrant Agent, and any resolution of
      the Board of Directors shall be sufficiently evidenced by a copy of the
      resolution certified by the Secretary or an Assistant Secretary to have
      been duly adopted by the Board of Directors of the Corporation, or by a
      committee of such Board of Directors or an officer of the Corporation
      appointed by the Board of Directors of the Corporation for such purpose,
      and to be in full force and effect on the date of such certification and
      delivered to the Warrant Agent (any such resolution, a "Board
      Resolution").

            (c)   The Warrant Agent may consult with counsel satisfactory to it,
      which may include counsel to the Corporation, and the written opinion of
      such 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 accordance with such written opinion.

            (d)   The Warrant Agent shall not be bound to make any investigation
      into the facts or matters stated in any Corporation Order or Board
      Resolution, but the

                                      -31-
<PAGE>
      Warrant Agent, in its discretion, may make such further inquiry or
      investigation into such facts or matters as it may see fit.

            (e)   The Warrant Agent, and any of its officers, directors and
      employees, in its individual or any other capacity, may become the Owner
      or Holder of, or acquire any interest in, any Warrants or other
      obligations of the Corporation, with the same rights that it or they would
      have if it were not the Warrant Agent hereunder, and, to the extent
      permitted by applicable law, it or they may engage or be interested in any
      financial or other transaction with the Corporation and may act on, or as
      depositary, trustee or agent for, any committee or body of Owners or
      Holders of Warrants or other obligations of the Corporation as freely as
      if it were not the Warrant Agent hereunder.

            (f)   The Warrant Agent shall not be under any liability for
      interest on any monies at any time received by it pursuant to any of the
      provisions of this Agreement or of the Warrants except as otherwise agreed
      with the Corporation, nor shall it be obligated to segregate such monies
      from other monies held by it, except as required by law.

            (g)   The Warrant Agent shall not be under any liability with
      respect to the validity or sufficiency of this Agreement or the execution
      and delivery hereof (except the due execution and delivery hereof by the
      Warrant Agent) or with respect to the validity or execution of the
      Warrants or the Warrant Certificates (except the countersignature
      thereof).

            (h)   The recitals contained herein and in the Warrants (except as
      to the Warrant Agent's countersignature thereon) shall be taken as the
      statements of the Corporation, and the Warrant Agent assumes no
      responsibility for the correctness thereof.

            (i)   The Warrant Agent shall not be accountable or under any duty
      or responsibility for the use by the Corporation of any of the Warrant
      Certificates countersigned by the Warrant Agent and delivered by it

                                      -32-
<PAGE>
      to the Corporation pursuant to this Agreement or for the application by
      the Corporation of any proceeds.

            (j)   The Warrant Agent shall have no duty or responsibility in case
      of any default by the Corporation in the performance of its covenants or
      agreements contained herein or in the Warrants or in the case of the
      receipt of any written demand from an Owner or Holder of a Warrant with
      respect to such default, including, without limitation, any duty or
      responsibility to initiate or attempt to initiate any proceedings at law
      or otherwise or, except as provided in Section 8.03, to make any demand
      upon the Corporation.

            (k)   In acting under this Agreement and in connection with the
      Warrants, the Warrant Agent is acting solely as the agent of the
      Corporation and does not assume any obligation or relationship of agency
      or trust for or with any of the Owners or Holders of the Warrants.

            Section 4.04. Compliance With Applicable Laws. The Warrant Agent
agrees to comply with all applicable federal and state laws imposing obligations
on it in respect of the services rendered by it under this Agreement and in
connection with the Warrants, including (but not limited to) the provisions of
United States federal income tax laws regarding information reporting and backup
withholding. The Warrant Agent expressly assumes all liability for its failure
to comply with any such laws imposing obligations on it, including (but not
limited to) any liability for its failure to comply with any applicable
provisions of United States federal income tax laws regarding information
reporting and backup withholding.

            Section 4.05. Corporate Warrant Agent Required; Eligibility. The
Corporation agrees, for the benefit of the Owners or Holders from time to time
of the Warrants, that there shall at all times be a Warrant Agent hereunder
until all of the Warrants have been exercised or are no longer exercisable,
which shall be a banking institution organized under the laws of the United
States of America or one of the states thereof and having an office or an
agent's office south of Chambers Street in the Borough of Manhattan, The City of
New York.

                                      -33-
<PAGE>
            Section 4.06. Resignation and Removal; Appointment of Successor. (a)
No resignation or removal of the Warrant Agent and no appointment of a successor
Warrant Agent pursuant to this Section 4.06 shall become effective until the
acceptance of appointment by the successor Warrant Agent under Section 4.07.

            (b) The Warrant Agent may resign at any time by giving written
notice of such resignation to the Corporation specifying such resignation and
the date on which it desires such resignation to become effective, provided
that, without the consent of the Corporation, such date shall not be less than
90 days after the date on which such notice is given. If an instrument of
acceptance by a successor Warrant Agent shall not have been delivered to the
Warrant Agent within 90 days after the giving of such notice of resignation, the
resigning Warrant Agent may petition any court of competent jurisdiction for the
appointment of a successor Warrant Agent with respect to the Warrants.

            (c) The Corporation may remove the Warrant Agent at any time by
giving written notice thereof to the Warrant Agent specifying such removal and
the date on which the Corporation desires such removal to become effective.

            (d) If at any time:

                  (i) the Warrant Agent shall cease to be eligible to act as
      such under Section 4.05 and shall fail to resign after the Corporation
      shall have delivered a written request therefor, or

                  (ii) the Warrant Agent shall become incapable of acting as
      such, or shall be adjudged a bankrupt or insolvent, or shall file a
      voluntary petition in bankruptcy or make an assignment for the benefit of
      its creditors or consent to the appointment of a receiver or custodian of
      all or any substantial part of its property, or shall admit in writing its
      inability to pay or meet its debts as they mature, or a receiver or
      custodian of it or of all or any substantial part of its property shall be
      appointed, or an order of any court shall be entered approving any
      petition filed by or against it under the provisions of any applicable
      bankruptcy or similar

                                      -34-
<PAGE>
      law, or any public officer shall take charge or control of the Warrant
      Agent or of its property or affairs, for the purpose of rehabilitation,
      conservation or liquidation, or

                  (iii) the Corporation shall elect to remove the Warrant Agent,
      provided that no default shall then exist with respect to the Warrants,

then in any such case, the Corporation by a Board Resolution may remove the
Warrant Agent with respect to all the Warrants.

            (e) If the Warrant Agent shall resign or be removed, or if a vacancy
shall occur in the office of the Warrant Agent for any other reason, the
Corporation, by a Board Resolution, shall promptly appoint a successor Warrant
Agent with respect to the Warrants, it being understood that at any time there
shall be only one Warrant Agent with respect to the Warrants.

            (f) The Corporation shall give notice to the Owners or Holders of
the Warrants of each resignation and each removal of the Warrant Agent and each
appointment of a successor Warrant Agent with respect to the Warrants in
accordance with Section 8.05. Each such notice shall include the name of the
successor Warrant Agent and the address of its Warrant Agent Office.

            Section 4.07. Acceptance of Appointment by Successor. (a) If a
successor Warrant Agent is appointed hereunder, such successor Warrant Agent so
appointed shall execute, acknowledge and deliver to the Corporation and to the
retiring Warrant Agent an instrument accepting such appointment, and thereupon
the resignation or removal of the retiring Warrant Agent shall become effective
and such successor Warrant Agent, without any further act, deed or conveyance,
shall become vested with all the rights, powers and duties of the retiring
Warrant Agent; provided, however, that on the request of the Corporation or the
successor Warrant Agent, such retiring Warrant Agent shall, upon payment of its
charges and disbursements then unpaid, execute and deliver an instrument
transferring to such successor Warrant Agent all the rights and powers of the
retiring Warrant Agent and shall duly assign, transfer and

                                      -35-
<PAGE>
deliver to such successor Warrant Agent all property and money held by such
retiring Warrant Agent hereunder.

            (b) Upon the request of any such successor Warrant Agent, the
Corporation shall execute any and all instruments for more fully and certainly
vesting in and confirming to such successor Warrant Agent all such rights and
powers referred to in Section 4.07(a).

            (c) No successor Warrant Agent shall accept its appointment, and no
such acceptance shall be effective, unless at the time of such acceptance such
successor Warrant Agent shall be qualified and eligible under this Article IV.

            Section 4.08. Merger, Conversion, Consolidation or Succession to
Business. Any corporation into which the Warrant 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 the Warrant Agent shall be
a party, or any corporation succeeding to all or substantially all of the
business of the Warrant Agent, shall be the successor of the Warrant Agent
hereunder, without the execution or filing of any paper or any further act on
the part of any of the parties hereto, provided that such corporation shall be
otherwise qualified and eligible under this Article IV. If any Warrant
Certificates shall have been countersigned, but not delivered, by the Warrant
Agent then in office, any successor by merger, conversion or consolidation to
such countersigning Warrant Agent may adopt such countersignature and deliver
the Warrant Certificates so countersigned with the same effect as if such
successor Warrant Agent had itself countersigned such Warrant Certificates.

                                    ARTICLE V

                CONSOLIDATION, MERGER, SALE, LEASE OR CONVEYANCE

            Section 5.01. Consolidations and Mergers of the Corporation and
Sales, Leases and Conveyances Permitted Subject to Certain Conditions. (a) The
Corporation may consolidate with, or sell, lease or convey all or substantially
all of its assets to, or merge with or into any other corporation, provided
that, in any such case,

                                      -36-
<PAGE>
(i) either the Corporation shall be the continuing corporation, or the successor
corporation shall be a corporation organized and existing under the laws of the
United States of America or a state thereof and such successor corporation shall
expressly assume, by Supplemental Agreement (as defined in Section 6.01(a))
satisfactory to the Warrant Agent and executed and delivered to the Warrant
Agent by such corporation, the due and punctual payment of the Cash Settlement
Value [or Cancellation Amount, as the case may be,] with respect to all
unexercised Warrants, according to their tenor, and the due and punctual
performance and observance of all of the covenants and conditions of this
Agreement to be performed by the Corporation, and (ii) the Corporation or such
successor corporation, as the case may be, shall not, immediately after such
merger or consolidation, or such sale, lease or conveyance, be in default in the
performance of any such covenant or condition. In case of any such
consolidation, merger, sale, lease or conveyance and upon such assumption by the
successor corporation, such successor corporation shall succeed to and be
substituted for the Corporation, with the same effect as if it had been named
herein as such, and the predecessor Corporation, except in the event of a lease,
shall be relieved of any further obligation hereunder or under the Warrants.
Such successor corporation thereupon may cause to be signed, and may issue
either in its own name or in the name of the Corporation, new Global Warrant
Certificates or Definitive Warrant Certificates, as the case may be,
representing Warrants not theretofore exercised, in exchange and substitution
for the Global Warrant Certificates and Definitive Warrant Certificates
theretofore issued; and upon the order of such successor corporation, instead of
the Corporation, and subject to all the terms, conditions and limitations in
this Agreement prescribed, the Warrant Agent shall countersign and shall deliver
the new Global Warrant Certificates or Definitive Warrant Certificates, as the
case may be, that such successor corporation shall have caused to be signed and
delivered to the Warrant Agent for countersignature. Such Global Warrant
Certificates or Definitive Warrant Certificates, as the case may be, shall in
all respects have the same legal rank and benefit under this Agreement as the
Warrant Certificates theretofore issued in accordance with the terms of this
Agreement as though such new Warrant Certificates had been issued at the

                                      -37-
<PAGE>
date of issue of the Warrant Certificates for which they are exchanged. In case
of any such consolidation, merger, sale, lease or conveyance, such changes in
phraseology and form (but not in substance) may be made in the new Warrant
Certificates as may be appropriate.

            (b) The Warrant Agent may receive a written opinion of counsel (who
may be an employee of the Corporation or other counsel acceptable to the Warrant
Agent) (an "Opinion of Counsel") as conclusive evidence that any such
consolidation, merger, sale, lease or conveyance, and any such assumption,
complies with the provisions of this Article V.

                                   ARTICLE VI

                             SUPPLEMENTAL AGREEMENTS

            Section 6.01. Amendment of Index Warrant Agreement. (a) This
Agreement and the Warrants may be amended by the Corporation, when authorized by
a Board Resolution, and the Warrant Agent (which amendment shall take the form
of a supplemental index warrant agreement) (each, a "Supplemental Agreement")),
without the consent of the Owners or Holders of the Warrants, for the purpose
of:

                  (i) curing any ambiguity or of curing, correcting or
      supplementing any defective or inconsistent provision contained herein or
      therein, or of making any other provisions with respect to matters or
      questions arising under this Agreement that shall not be inconsistent with
      the provisions of this Agreement or the Warrants; or

                  (ii) evidencing the succession of another corporation to the
      Corporation and the assumption by any such successor of the covenants of
      the Corporation contained herein and in the Warrants in accordance with
      Article V; or

                  (iii) appointing a successor Depository in accordance with
      Section 1.01(e); or

                  (iv) evidencing and providing for the acceptance of
      appointment hereunder by a successor Warrant Agent in accordance with
      Section 4.07; or

                                      -38-
<PAGE>
                  (v) adding to the covenants of the Corporation for the benefit
      of the Owners or Holders of the Warrants or surrendering any right or
      power herein conferred upon the Corporation; or

                  (vi) issuing Warrants in the form of Definitive Warrant
      Certificates in accordance with Section 1.01(c); or

                  (vii) amending this Agreement and the Warrants in any manner
      that the Corporation may deem to be necessary or desirable and that will
      not materially and adversely affect the interests of the Owners or Holders
      of the Warrants.

            (b) The Corporation and the Warrant Agent may amend this Agreement
and the Warrants (which amendment shall take the form of a Supplemental
Agreement), with the consent of the Owners or Holders, as the case may be, of
not fewer than 66-2/3% in number of the unexercised Warrants affected by such
amendment, for the purpose of adding any provisions to or changing in any manner
or eliminating any of the provisions of this Agreement or of modifying in any
manner the rights of the Owners or Holders of the Warrants under this Agreement;
provided, however, that, without the consent of each Owner or Holder affected
thereby, no such amendment may be made that changes the determination of the
Cash Settlement Value [or Cancellation Amount, as the case may be,] of the
Warrants (or any aspects of such determination) so as to reduce the amount
receivable upon exercise or deemed exercise of the Warrants, shortens the period
of time during which the Warrants may be exercised, or otherwise materially and
adversely affects the exercise rights of the Owners or Holders, as the case may
be, or reduces the number of unexercised Warrants the consent of the Owners or
Holders of which is required for amendment of this Agreement or the Warrants.
The Corporation and the Warrant Agent shall be entitled to rely upon
certification in form satisfactory to each of them that any requisite consent
has been obtained from the Owners of Warrants represented by a Global Warrant
Certificate. Such certification may be provided by Depository Participants
acting on behalf of such Owners of Warrants, provided that any such
certification is accompanied by a certification from the Depository as to

                                      -39-
<PAGE>
the Global Warrant Certificate holdings of such Depository Participants.

            Section 6.02. Form of Approval of Supplemental Agreements by Owners
or Holders. It shall not be necessary for the Owners or Holders of the Warrants
to approve the particular form of any proposed Supplemental Agreement, but it
shall be sufficient if the Owners or Holders, as the case may be, shall approve
the substance of the Supplemental Agreement.

            Section 6.03. Effect of Supplemental Agreements. Upon the execution
of any Supplemental Agreement under this Article, this Agreement shall be
modified in accordance therewith, such Supplemental Agreement shall form a part
of this Agreement for all purposes, and, subject to the proviso to the first
sentence of Section 6.01(b), every Owner or Holder of Warrants theretofore or
thereafter countersigned and delivered hereunder shall be bound thereby.

            Section 6.04. Reference in Warrants to Supplemental Agreements.
Warrants countersigned and delivered after the execution of any Supplemental
Agreement pursuant to this Article may, and shall if required by the Warrant
Agent, bear a notation in form approved by the Warrant Agent as to any matter
provided for in such Supplemental Agreement. If the Corporation shall so
determine, new Warrants so modified as to conform, in the opinion of the Warrant
Agent and the Corporation, to any such Supplemental Agreement may be prepared
and executed by the Corporation and countersigned and delivered by the Warrant
Agent in exchange for unexercised Warrants.

                                   ARTICLE VII

                          COVENANTS OF THE CORPORATION

            Section 7.01. Listing of Warrants on National Securities Exchange.
(a) The Corporation covenants, for the benefit of the Owners or Holders of the
Warrants, as the case may be, that (i) it will seek to obtain the listing of the
Warrants on [name of national

                                      -40-
<PAGE>
securities exchange] and (ii) until the Expiration Date, it will not seek the
delisting of the Warrants from, or permanent suspension of their trading on,
[name of national securities exchange] unless prior to such delisting or
suspension the Warrants shall have been listed, and shall be trading, on another
national securities exchange.

            (b) The Corporation shall advise the Warrant Agent of the date of
any expected delisting or permanent suspension of trading of the Warrants as
soon as is practicable and will immediately inform the Warrant Agent after the
Corporation has received notice that such delisting or suspension has occurred,
but in no event shall notice of such delisting or suspension be given to the
Warrant Agent later than [3:00 P.M.], New York City time, on the fifth New York
Business Day preceding the date that such delisting or suspension occurs.

            (c) The Corporation shall notify the Owners or Holders of the
Warrants in accordance with Section 8.05 as promptly as is practicable of any
expected delisting or suspension of trading of the Warrants.

            Section 7.02. Governmental Approvals. The Corporation shall from
time to time take all reasonable action necessary to obtain and keep effective
any and all permits, consents and approvals of governmental agencies and
authorities and the [name of national securities exchange], and shall make all
filings under United States federal and state laws, that may be or become
requisite in connection with the issuance, sale, trading, transfer, delivery or
exercise of the Warrants, each Global Warrant Certificate and each Definitive
Warrant Certificate.

            Section 7.03. Payment of Cash Settlement Value [or Cancellation
Amount]. The Corporation agrees, for the benefit of the Owners or Holders of the
Warrants, that it will duly and punctually pay the Cash Settlement Value [or
Cancellation Amount, as the case may be,] on each Warrant in accordance with the
terms of the Warrants and this Agreement, and that the right of each such Owner
or Holder, as the case may be, to receive payment of the Cash Settlement Amount
[or Cancellation Amount, as the case may be,] on such Warrant when such amount
is due and payable shall be absolute and unconditional.

            Section 7.04. Maintenance of Office or Agency; Unclaimed Moneys. (a)
The Corporation shall maintain an office and agency at which the Warrants may be
presented or

                                      -41-
<PAGE>
surrendered for exercise or registration of transfer or exchange or cancellation
and where notices and demands to or upon the Corporation in respect of the
Warrants and this Agreement may be served, which office and agency shall be the
same as the location of the Warrant Agent Office, and the Corporation hereby
appoints the Warrant Agent as its agent to receive all such presentations,
surrenders, notices and demands.

            (b) The Corporation shall, on or prior to each due date of the Cash
Settlement Value [or Cancellation Amount, as the case may be,] on any Warrant,
deposit with the Warrant Agent a sum sufficient to pay the Cash Settlement Value
[or Cancellation Amount, as the case may be,] so becoming due, such sum to be
held for the benefit of the Persons entitled to such Cash Settlement Value [or
Cancellation Amount, as the case may be].

            (c) Any money deposited with the Warrant Agent for the payment of
the Cash Settlement Value [or Cancellation Amount, as the case may be,] on any
Warrant and remaining unclaimed for three years after such Cash Settlement Value
[or Cancellation Amount, as the case may be,] has become due and payable, shall
be paid to the Corporation, at the request of the Corporation, and the Person
entitled to such money shall thereafter, as an unsecured general creditor, look
only to the Corporation for payment thereof, and all liability of the Warrant
Agent with respect to such money shall thereupon cease; provided, however, that
the Warrant Agent, before being required to make any such repayment, may at the
expense of the Corporation, cause notice to be given in accordance with Section
8.05 to the Person entitled to such money that such money remains unclaimed and
that, after a date specified therein, which shall be not less than 30 days from
the date of such notice, any unclaimed balance of such money then remaining will
be repaid to the Corporation.

            Section 7.05. Corporate Existence. Subject to Article V, the
Corporation shall do or cause to be done all things necessary to preserve and
keep in full force and effect its corporate existence, rights (charter and
statutory) and franchises; provided, however, that the Corporation shall not be
required to preserve any right or franchise if its Board of Directors or a
committee thereof shall determine that the preservation thereof is no longer

                                      -42-
<PAGE>
desirable in the conduct of the business of the Corporation and that the loss
thereof is not disadvantageous in any material respect to the Owners or Holders
of the Warrants, as the case may be.

                                  ARTICLE VIII

                                  MISCELLANEOUS

            Section 8.01. Reopening of Issue of Warrants. The Corporation may,
from time to time, issue additional Warrants under this Agreement. All Warrants
issued hereunder, from and after the date they are issued, shall be identical.

            Section 8.02. Payment of Taxes. The Corporation shall pay all
documentary stamp taxes attributable to the initial issuance of Warrants;
provided, however, that the Corporation shall not be required to pay any tax or
other governmental charge that may be payable in respect of any transfer
involving any beneficial or record interest in or ownership interest of any
Warrants.

            Section 8.03. Notices and Demands to the Corporation and Warrant
Agent. If the Warrant Agent shall receive any notice or demand addressed to the
Corporation by any Owner or Holder pursuant to the provisions of the Warrants,
the Warrant Agent shall promptly forward such notice or demand to the
Corporation.

            Section 8.04. Addresses for Notices. Any communications from the
Corporation to the Warrant Agent with respect to this Agreement shall be
addressed to [name of Warrant Agent], [address] (facsimile: (___) ___-____)
(telephone: (___) ___-____), Attention: [Corporate Trust Department]; any
communications from the Warrant Agent to the Corporation with respect to this
Agreement shall be addressed to UBS AG, 299 Park Avenue, New York, New York
10017 (facsimile: (212) ___-____) (telephone: (212) ___-____), Attention:
[Robert Dinerstein] (or, in either case, at such other address as shall be
specified in writing to the other by the Warrant Agent or the Corporation, as
the case may be).

            Section 8.05. Notices to Owners and Holders. The Corporation or the
Warrant Agent shall give any notice

                                      -43-
<PAGE>
to be given to the Owners of Book-Entry Warrants by providing the Depository
with a form of notice to be distributed by the Depository to Depository
Participants in accordance with the customs and practices of the Depository. The
Corporation or the Warrant Agent shall give notice to the Holders of
Certificated Warrants by mailing written notice by first class mail, postage
prepaid, to such Holders as their names and addresses appear in the Warrant
Register.

            Section 8.06. GOVERNING LAW. THIS AGREEMENT AND EACH WARRANT ISSUED
HEREUNDER SHALL BE GOVERNED BY AND CONSTRUED IN ACCORDANCE WITH THE LAWS OF THE
STATE OF NEW YORK.

            Section 8.07. Benefits of Index Warrant Agreement. Nothing in this
Agreement or in the Warrants expressed or implied and nothing that may be
inferred from any of the provisions hereof or thereof is intended, or shall be
construed, to confer upon, or give to, any Person other than the Corporation,
the Warrant Agent and their respective successors and assigns, and the Owners or
Holders of the Warrants, as the case may be, any right, remedy or claim under or
by reason of this Agreement or the Warrants or of any covenant, condition,
stipulation, promise or agreement hereof or thereof, and all covenants,
conditions, stipulations, promises and agreements contained in this Agreement or
in the Warrants shall be for the sole and exclusive benefit of the Corporation
and the Warrant Agent and their respective successors and assigns and of the
Owners or Holders of the Warrants, as the case may be.

            Section 8.08. Successors and Assigns. All covenants and agreements
in this Agreement by the Corporation shall bind its successors and assigns,
whether so expressed or not.

            Section 8.09. Index Warrant Agreement and Warrants Solely Corporate
Obligations. No recourse for the payment of the Cash Settlement Value [or
Cancellation Amount, as the case may be,] of any Warrant or for any claim based
on any Warrant or this Agreement shall be had against any director or officer or
stockholder, past, present or future, of the Corporation. Any such claim against
any such Person is expressly waived as a condition

                                      -44-
<PAGE>
of, and as consideration for, the execution and delivery of this Agreement and
the issue of the Warrants.

            Section 8.10. Severability. If any provision in this Agreement or in
the Warrants shall be invalid, illegal, or unenforceable in any jurisdiction,
the validity, legality and enforceability of the remaining provisions, or of
such provisions in any other jurisdiction, shall not in any way be affected or
impaired thereby.

            Section 8.11. Headings. The descriptive headings of the several
Articles and Sections and the Table of Contents of this Agreement are for
convenience only and shall not control or affect the meaning or construction of
any of the provisions hereof.

            Section 8.12. Counterparts. This Agreement may be executed by the
parties hereto in any number of counterparts, each of which when so executed and
delivered shall be deemed to be an original, but all such counterparts shall
together constitute but one and the same instrument.

            Section 8.13. Inspection of Index Warrant Agreement. A copy of this
Agreement shall be available at all reasonable times at the Warrant Agent Office
for inspection by the Owners or Holders of the Warrants, as the case may be, the
Depository Participants and the Indirect Participants. In the case of
Certificated Warrants, the Warrant Agent may require the Holder of such Warrant
to submit such Holder's Warrant Certificate for inspection by the Warrant Agent.

                                      -45-
<PAGE>
            IN WITNESS WHEREOF, this Index Warrant Agreement has been duly
executed by the parties hereto as of the day and year first above written.

                                    UBS AG

                                    By:__________________________
                                       Name:
                                       Title:

[SEAL]

Attest:

__________________________
[Assistant] Secretary

                                    [NAME OF WARRANT AGENT], as Warrant Agent

                                    By:__________________________
                                       Name:
                                       Title:

[SEAL]

Attest:

__________________________
[Assistant] Secretary

                                      -46-
<PAGE>
                                                                       EXHIBIT A

             [WARRANTS EVIDENCED BY THIS WARRANT CERTIFICATE CANNOT
                   BE EXERCISED PRIOR TO ________ __, 200__.]

               [NO PAYMENT WILL BE MADE UPON THE EXERCISE OF THIS
                  WARRANT UNLESS THE WARRANT AGENT HAS RECEIVED
                    THE CERTIFICATION DESCRIBED IN THE INDEX
                               WARRANT AGREEMENT]

                    EXERCISABLE ONLY IF COUNTERSIGNED BY THE
                        WARRANT AGENT AS PROVIDED HEREIN

                   VOID AFTER [3:00 P.M.], NEW YORK CITY TIME,
                              ON ________ __, 200__

         No. _________                               CUSIP No. ____________

                           GLOBAL WARRANT CERTIFICATE
                                  representing
               ________ [Name of Index] Index [Put/Call] Warrants
                           Expiring ________ __, 200__

                                     UBS AG

            This certifies that [______________] or registered assigns is the
registered holder of [insert number initially issued] [insert name of Index]
Index [Put/Call] Warrants (the "Warrants"), or such lesser amount as is
indicated in the records of [name of Warrant Agent], as Warrant Agent. Each
Warrant entitles the [beneficial owner thereof (an "Owner")] [registered holder
thereof (a "Holder")], subject to the provisions contained herein and in the
Index Warrant Agreement referred to below, to receive from UBS AG, a New York
corporation (the "Corporation"), the Cash Settlement Value (as defined below)
[or Cancellation Amount (as defined below), as the case may be,] thereof in
[U.S. dollars (specify other currency if applicable)], as further described
below. [No exercise price shall be payable by any Holder or Owner in connection
with the exercise of any Warrant.] [The exercise price for each Warrant shall be
$_____ and shall be payable in [U.S. dollars (specify other currency if
applicable)] (the "Exercise Price").] In no event shall any [Owner] [Holder] be
entitled to any interest on the

                                      A-1
<PAGE>
Cash Settlement Value [or Cancellation Amount] (unless the Corporation shall
default in the payment of such Cash Settlement Value).

            Subject to the terms of the Index Warrant Agreement, each Warrant
may be exercised or deemed to be exercised in whole but not in part on any New
York Business Day (as defined below) from [the date of issuance (specify other
date if applicable)] until [3:00 P.M.], New York City time, on the earlie[st] of
(i) [_________ (specify date upon which right to exercise Warrants expires)] or,
if such date is not a New York Business Day, on the next succeeding New York
Business Day (the "Expiration Date"), [or] (ii) the date of automatic exercise
[or (iii) the date of cancellation], as further described below and as provided
in the Index Warrant Agreement. Except in the case of automatic exercise or any
exercise on the Expiration Date, not fewer than [(specify minimum exercise
amount)] [nor more than [(specify maximum exercise amount)] Warrants may be
exercised by or on behalf of any one [Owner] [Holder] at any one time.
References herein to "U.S. dollars", "U.S.$" or "$" are references to the
currency of the United States of America. References to "[(insert name of Index
currency)]" or "[_______]" are references to the currency of [name of Index
country]. As used herein, the term "New York Business Day" means any day other
than a Saturday or Sunday or a day on which the New York Stock Exchange or the
American Stock Exchange [or (list any other relevant securities exchanges)] is
not open for securities trading or banking institutions generally in The City of
New York are authorized or required by law or executive order to close; "Index
Country Business Day" means any day other than (i) a Saturday or a Sunday or a
day on which banking institutions generally in [(specify name of Index country)]
are authorized or required by law or executive order to close or (ii) a day on
which the [names of relevant stock exchanges] are not open for business[; and
"Index Country Resident" means a resident of, or any corporation or other Person
organized under the laws of [(specify name of Index country)], its territories,
its possessions or other areas subject to its jurisdiction].

            This [Global] [Definitive] Warrant Certificate is issued under and
in accordance with the Index Warrant Agreement, dated as of ________ __, 200__
(the "Index Warrant Agreement"), between the Corporation and the

                                      A-2
<PAGE>
Warrant Agent, and is subject to the terms and provisions contained in the Index
Warrant Agreement, to all of which terms and provisions all [Owners] [Holders]
of the Warrants represented by this [Global] [Definitive] Warrant Certificate
[and the Holder of this Global Warrant Certificate] consent by acceptance hereof
[by the Depository (as defined below)]. Copies of the Index Warrant Agreement
are on file at the Warrant Agent Office at ______________, New York, New York,
_____, Attention: Corporate Trust Department, or at such other office as may be
specified in a notice given to the [Owners] [Holders] of the Warrants. [Except
as provided in the Index Warrant Agreement, Owners will not be entitled to
receive definitive certificates evidencing their Warrants. Warrant holdings will
be held through a depository selected by the Corporation, which initially is
[The Depository Trust Company], or its agent (the "Depository", which term, as
used herein, includes any successor depository selected by the Corporation) as
further provided in the Index Warrant Agreement.]

            Capitalized terms included herein but not defined herein have the
meanings assigned to them in the Index Warrant Agreement.

            The Cash Settlement Value of any Exercised Warrants (whether
exercised automatically or by Exercise Notice) shall mean [__________________
(specify fraction)] of the U.S. dollar equivalent (rounded to the nearest
dollar) of the amount, if any, by which [(i) the Strike Index (as defined below)
exceeds (ii) the Spot Index (as defined below) on the Valuation Date (as defined
below) with respect to such Exercised Warrant] [the amount, if any, by which (i)
the Spot Index (as defined below) on the Valuation Date (as defined below) with
respect to such Exercised Warrant exceeds (ii) the Strike Index]; provided that
if such amount is less than zero, the Cash Settlement Value shall be zero. [The
Cancellation Amount of any Exercised Warrants shall mean [Insert method for
determining amount].] The "Spot Index" on any date shall mean [Insert amount or
method for determining amount]. The "Strike Index" of any Exercised Warrant
shall mean [Insert amount or method for determining amount]. The exchange rate
(or manner of calculating such rate) for conversion of the Cash Settlement
Value, [the Cancellation Amount,] the Strike Index, the Spot Index and/or the
value of Underlying

                                      A-3
<PAGE>
Securities, as applicable, into U.S. dollars shall be [_____________ (specify
such rate or manner of calculating such rate)] and shall be determined by the
Warrant Agent.

            Except in the case of automatic exercise [or cancellation] as
further provided below and in the Index Warrant Agreement, and subject to any
Maximum Exercisable Number of Warrants, the "Valuation Date" for any Warrant
shall be the first Index Country Business Day next succeeding the "Exercise
Date", which shall be the New York Business Day on which the Warrant Agent has
received (i) delivery of [such Warrant on the records of the Depository free to
the Warrant Account] [the Definitive Warrant Certificate representing such
Warrant at the Warrant Agent Office][, (ii) the Exercise Price] and ([iii]) an
Exercise Notice for such Warrant in good order in the form of [Exhibit B-1]
[Exhibit B-2] to the Index Warrant Agreement, [which shall include certification
that the [exercising Owner] [Holder] is not an Index Country Resident,] at or
prior to [3:00 P.M.], New York City time; provided that if the Warrant Agent
receives such Warrant[, the Exercise Price] or the Exercise Notice after [3:00
P.M.] on such day, the "Exercise Date" shall be the next succeeding New York
Business Day and such Warrant[, Exercise Price] and Exercise Notice shall be
deemed to have been received on such next succeeding New York Business Day. Any
delivery of a Warrant or Exercise Notice received after [3:00 P.M.], New York
City time, on the Expiration Date shall be void and of no effect and shall be
deemed not to have been delivered. [A [Depository Participant] [Holder] may
specify in its irrevocable Exercise Notice in relation to a Warrant that such
Exercise Notice is conditional (a "Conditional Exercise Notice"), and in such
case such Conditional Exercise Notice shall be void and of no effect and shall
be disregarded for all purposes of the Index Warrant Agreement if [Describe the
terms upon which the Exercise Notice may be conditional, which may be as
follows: the Spot Index on the day that, but for the provisions of this
sentence, would be the Valuation Date for such Warrant is more than
[_________________] [above] [below] the Spot Index on the [Designated] Exercise
Date of such Warrants (or, if such date is not an Index Country Business Day, on
the immediately preceding Index Country Business Day) (the "Reference Value").]

                                      A-4
<PAGE>
            By [5:00 P.M.], New York City time, on the New York Business Day on
which such Exercise Notice is received (or deemed to have been received), the
Warrant Agent shall notify the Corporation (and such other parties (not to
exceed two) as the Corporation shall designate in writing) of the number of
Warrants in respect of which Exercise Notices, not rejected pursuant to the
Index Warrant Agreement, were received (or deemed to have been received) at or
prior to [3:00 P.M.], New York City time, on such date, the number of such
Exercise Notices that were rejected by the Warrant Agent pursuant to the Index
Warrant Agreement and the number of Warrants to which such rejected Exercise
Notices relate [and the number of such Exercise Notices that were Conditional
Exercise Notices (and the number of Warrants to which such Conditional Exercise
Notices relate)]. By [5:00 P.M.], New York City time, on the Valuation Date for
such Warrants (or if such Valuation Date is not a New York Business Day, then
the next succeeding New York Business Day), the Warrant Agent shall (i) [(x)
after obtaining the Reference Value and the Spot Index for such Valuation Date,
determine whether any Conditional Exercise Notices have become void pursuant to
Section 2.02(b) of the Index Warrant Agreement, and if so, promptly notify the
Corporation (and such other parties (not to exceed two) as the Corporation shall
designate in writing) and send a Rejection Notice in the form of Exhibit C to
the Index Warrant Agreement to the appropriate [Depository Participant] [Holder]
and redeliver such Warrants to such [Depository Participant] [Holder] as
provided in the Index Warrant Agreement and (y)] determine the aggregate number
of [Tendered] [Exercised] Warrants, (ii) [determine pursuant to Section 2.02(f)
of the Index Warrant Agreement the number of such Tendered Warrants which shall
be Exercised Warrants, (iii)] determine the Cash Settlement Value (in the manner
provided in Section 2.02(h) of the Index Warrant Agreement) of the Exercised
Warrants, (iv) notify the Corporation (and such other parties (not to exceed
two) as the Corporation shall designate in writing) of the Cash Settlement Value
with respect to such Warrants, (v) send notice of confirmation of exercise in
substantially the form of Exhibit D to the Index Warrant Agreement to the
appropriate [Depository Participant] [Holder] and (vi) notify the Corporation
(and such other parties (not to exceed two) as the Corporation shall designate
in writing) of such other matters relating

                                      A-5
<PAGE>
to the Exercised Warrants as the Corporation shall reasonably request.

            If the Corporation has made adequate funds available to the Warrant
Agent in a timely manner as provided in the Index Warrant Agreement, the Warrant
Agent will make payment in the form of a wire transfer to the appropriate
Depository Participant on the [fifth] New York Business Day following the
Valuation Date (or, if such Valuation Date is not a New York Business Day, on
the [sixth] New York Business Day after such Valuation Date) (the "Settlement
Date"), all as provided in the Index Warrant Agreement, such payment to be in
the amount of the Cash Settlement Value in respect of Exercised Warrants
exercised by such Depository Participant. [The Warrant Agent shall have no
responsibility for the crediting by such Depository Participant of the Cash
Settlement Value of such Warrants to the appropriate Owners.]

            [The Warrant Agent will cause its records to be marked to reflect
the reduction in the number of Warrants represented by this Global Warrant
Certificate by the number of Warrants for which payment has been made in
accordance with the Index Warrant Agreement.] [If this Definitive Warrant
Certificate shall be surrendered to the Warrant Agent for exercise of fewer than
all the Warrants represented hereby, the Warrant Agent shall issue and deliver
to the Holder of the Warrants represented hereby by first class mail at the
expense of the Corporation a Definitive Warrant Certificate representing all
Warrants remaining unexercised after such exercise.]

            All Warrants with respect to which (i) there has been no proper
delivery of Warrants to the Warrant Account and no valid Exercise Notice has
been received by the Warrant Agent at or prior to [3:00 P.M.], New York City
time, on the earlier to occur of (A) the Expiration Date for such Warrants and
(B) the last New York Business Day prior to the effective date on which the
Warrants are delisting from, or permanently suspended from trading on, the [name
of national securities exchange] without being accepted for listing on or prior
to such New York Business Day on another United States national securities
exchange (such New York Business Day, the "Delisting Date"), (ii) the Exercise
Date has been postponed pursuant to Section 2.02(f) of the Index Warrant
Agreement to a date on

                                      A-6
<PAGE>
or after the earlier of the Expiration Date and the Delisting Date, [or (iii)
list other events causing automatic exercise of Warrants, if applicable] will be
automatically exercised on such Expiration Date or Delisting Date [or on the
date on which (list other dates of automatic exercise)] (any such date, a
"Deemed Exercise Date") without any requirement of notice of exercise to the
Warrant Agent. The Valuation Date for such Warrants shall be the first Index
Country Business Day following such Deemed Exercise Date.

            If the Corporation has made adequate funds available to the Warrant
Agent in a timely manner as set forth in the Index Warrant Agreement, the
Warrant Agent will make its payment available in the form of [a wire transfer to
the appropriate Depository Participant] [one or more cashier's checks or
official bank checks to the appropriate Holder] in the amount of [(x)] the Cash
Settlement Amount with respect to each Warrant [minus (y) the Exercise Price],
after [3:00 P.M.], New York City time, but prior to the close of business, on
the [eighth] New York Business Day following the Valuation Date for such
automatically exercised Warrants (or, if such Valuation Date is not a New York
Business Day, on the [ninth] New York Business Day after such Valuation Date),
such payment to be in the amount of the aggregate Cash Settlement Value in
respect of Warrants that have been automatically exercised, all as provided in
the Index Warrant Agreement; provided, however, that the Warrant Agent shall
withhold any such payment with respect to any Warrants for which the Warrant
Agent has not received [(i)] the related Warrants through transfer of such
Warrants to the Warrant Account[, and (ii) certification that the Owner of such
Warrants is not an Index Country Resident, dated no earlier than the Deemed
Expiration Date and in the form of Exhibit E-1 to the Index Warrant Agreement].
When payment has been made in respect of all automatically exercised Warrants
represented by this Warrant Certificate, the Warrant Agent shall, promptly upon
receipt cancel this Warrant Certificate and deliver it to the Corporation.

            If the Index is not calculated and announced by the [name of Index
Publisher] (the "Index Publisher") on a Valuation Date but is calculated and
publicly announced by another Person not affiliated with the Corporation and
acceptable to the Corporation (the "Third Party"), the

                                      A-7
<PAGE>
applicable Cash Settlement Value [or Cancellation Amount] shall be calculated by
reference to the value of the closing quotation for the Index so calculated and
announced by the Third Party.

            If, prior to any Valuation Date, the Index Publisher or the Third
Party makes a material change in the formula for or the method of calculating
the Index, the Corporation shall promptly appoint an investment or commercial
bank of international standing that is not an affiliate of the Corporation (the
"Independent Expert") who shall make such calculations as may be required to
determine the applicable Cash Settlement Value [or Cancellation Amount] using
the formula and method of calculating the Index as in effect prior to such
change or modification.

            If, on any Valuation Date, neither the Index Publisher nor any Third
Party is calculating and disseminating the Index and neither is providing any
successor index, the Corporation shall promptly appoint an Independent Expert
who shall make such calculations as it determines may be required to determine
the applicable Cash Settlement Value [or Cancellation Amount] using the formula
and method of calculating the Index as in effect on the date the Index was last
so calculated.

            If any of the events referred to above with respect to the
calculation of the Index shall occur, the Corporation shall promptly make
available information regarding the composition, method of calculation and
current level of the Index or successor index upon written request to the
Corporation's offices at UBS AG, 299 Park Avenue, New York, New York 10017,
Attention: Robert Dinerstein. In addition, the Corporation shall undertake
reasonable efforts to ensure that such information is publicly available. If the
Index Publisher shall elect to suspend or discontinue calculating or announcing
the Index, the Corporation shall so notify the Owners by giving notice to the
Depository in accordance with the Index Warrant Agreement.

            The Corporation, the Warrant Agent and any agent of the Corporation
or the Warrant Agent may deem and treat the registered Holder hereof as the
absolute Holder of all right, title and interest in the Warrants evidenced
hereby

                                      A-8
<PAGE>
(notwithstanding any notation of ownership or other writing hereon) for any
purpose and as the Person entitled to exercise the rights represented by the
Warrants evidenced hereby, and neither the Corporation nor the Warrant Agent nor
any agent of the Corporation or the Warrant Agent shall be affected by any
notice to the contrary, except that the Corporation and the Warrant Agent shall
be entitled to rely on and act pursuant to instructions of Depository
Participants as contemplated herein and in the Index Warrant Agreement.

            Subject to the terms of the Index Warrant Agreement, upon due
presentment for registration of transfer or exchange of this [Global]
[Definitive] Warrant Certificate at the Warrant Agent Office, the Corporation
shall execute and the Warrant Agent shall countersign and deliver in the name of
the designated transferee a new [Global] [Definitive] Warrant Certificate or
[Global] [Definitive] Warrant Certificates of like tenor and representing in the
aggregate a like number of unexercised Warrants as evidenced by this [Global]
[Definitive] Warrant Certificate at the time of such registration of transfer,
which shall be issued to the designated transferee in exchange for this [Global]
[Definitive] Warrant Certificate, subject to the limitations provided in the
Index Warrant Agreement, without charge.

            This [Global] [Definitive] Warrant Certificate and the Index Warrant
Agreement are subject to amendment as provided in the Index Warrant Agreement.

            THIS [GLOBAL] [DEFINITIVE] WARRANT CERTIFICATE SHALL BE GOVERNED BY
AND CONSTRUED IN ACCORDANCE WITH THE LAWS OF THE STATE OF NEW YORK.

            This [Global] [Definitive] Warrant Certificate shall not be valid or
obligatory for any purpose until countersigned by the Warrant Agent.

                                      A-9
<PAGE>
            IN WITNESS WHEREOF, the Corporation has caused this instrument to be
duly executed under its corporate seal.

Dated as of ________ __, 200__

                                    UBS AG

                                    By:__________________________
                                       Name:
                                       Title:

                                    By:__________________________
                                       Name:
                                       Title:

Countersigned on the date above written:

[NAME OF WARRANT AGENT],
 as Warrant Agent

By:___________________________
   Name:
   Title:

                                      A-10
<PAGE>
                                                                     EXHIBIT B-1

                             Form of Exercise Notice
            for Warrants Represented by a Global Warrant Certificate

[NAME OF WARRANT AGENT],
 as Warrant Agent
[address]
Facsimile:  ________________
Telephone:  ________________

Attention:

      Re:   Exercise of UBS AG [name of Index] Index [Put/Call] Warrants
            Expiring ________ __, 200__ (the "Warrants")

            1. We refer to the Index Warrant Agreement, dated as of ________ __,
200__ (the "Index Warrant Agreement"), between UBS AG (the "Corporation") and
[Name of Warrant Agent], as Warrant Agent (the "Warrant Agent"). On behalf of
certain beneficial owners, each of whom is exercising no fewer than [__________]
Warrants covered by this Notice and whose Warrants are held through the
Depository in our name, we hereby irrevocably exercise [_____________] Warrants
(the "Tendered Warrants").

            2. This Exercise Notice [is] [is not] a Conditional Exercise Notice.
[We hereby acknowledge that a Conditional Exercise Notice will be void and of no
effect (and shall be disregarded for all purposes under the Index Warrant
Agreement) if the Spot Index on the date that, but for the provisions of Section
2.02(b) of the Index Warrant Agreement, would be the Valuation Date for the
Warrants is more than [__________] [above] [below] the Spot Index on the
[Designated] Exercise Date (or, if the [Designated] Exercise Date is not an
Index Country Business Day, on the immediately preceding Index Country Business
Day).]

            3. We have instructed the Depository to deliver the Exercised
Warrants free through the Depository to the Warrant Account [Account No.
_______________])[, and we have made payment of the Exercise Price as provided
in Section 2.01(b) of the Index Warrant Agreement].

            4. We hereby acknowledge that this Exercise Notice[, the Exercise
Price] and the Tendered Warrants must
<PAGE>
be received by you by [3:00 P.M.], New York City time, on a New York Business
Day in order for the Valuation Date of the Tendered Warrants to be the Index
Country Business Day next succeeding such New York Business Day, and that if
this Exercise Notice[, the Exercise Price] or the Tendered Warrants are received
by you after [3:00 P.M.], New York City time, but prior to the close of business
on a New York Business Day, the Valuation Date of the Tendered Warrants shall be
the Index Country Business Day next succeeding the first New York Business Day
following the day on which this Exercise Notice[, the Exercise Price] and the
Tendered Warrants are received. [We further acknowledge that if this Conditional
Exercise Notice[, the Exercise Price] or the Tendered Warrants are received by
you after [3:00] P.M., New York City time, but prior to the close of business on
a New York Business Day, that for purposes of making the determinations required
by such Conditional Exercise Notice, the Warrants will be deemed to be exercised
on the New York Business Day next succeeding the day on which this Exercise
Notice[, the Exercise Price] and the Tendered Warrants are received.]

            5. We hereby certify that we are a participant of [The Depository
Trust Company] (the "Depository") with the present right to use and receive its
services.

            6. We hereby acknowledge that if you determine that this Exercise
Notice has not been duly completed, or is not in proper form, or you are unable
to verify that we are a participant of the Depository as provided above, this
Exercise Notice will be void and of no effect and will be deemed not to have
been delivered.

            7. We hereby direct you to make payment to us of amounts payable to
the beneficial owners of the Tendered Warrants as a result of the exercise of
the Tendered Warrants hereunder as follows:

                                     B-1-2
<PAGE>
            [ ]         By cashier's check or an official bank
                        check;

or

            [ ]         By wire transfer to the following U.S.
                        dollar bank account in the United
                        States:

                        (Minimum payments of $100,000 only)

                        Bank:________________

                        Account No.:_____________

                        ABA Routing No.:___________

                        Reference:______________

           [8. We hereby certify that none of the clients on whose behalf we are
exercising the above referenced Warrants are Index Country Residents.]

            Capitalized terms used herein and not defined have the meanings
assigned to them in the Index Warrant Agreement.

Dated: ________ __, 200__

                                          [NAME OF DEPOSITORY
                                           PARTICIPANT]
                                          [Participant Number]

                                          By:_____________________
                                             Name:
                                             Title:

                                             [Address]
                                             Telephone:
                                             Facsimile:

                                     B-1-3
<PAGE>
                                                                     EXHIBIT B-2

                             Form of Exercise Notice
                    for Warrants Represented by a Definitive
                               Warrant Certificate

[NAME OF WARRANT AGENT],
 as Warrant Agent
[address]
Facsimile:  ________________
Telephone:  ________________

Attention:

      Re:   Exercise of UBS AG [name of Index] Index [Put/Call] Warrants
            Expiring ________ __, 200__ (the "Warrants")

            1. We refer to the Index Warrant Agreement, dated as of ________ __,
200__ (the "Index Warrant Agreement"), between UBS AG (the "Corporation") and
[Name of Warrant Agent], as Warrant Agent (the "Warrant Agent"). We hereby
irrevocably exercise [_____________] Warrants (the "Tendered Warrants") and
deliver to you herewith a Definitive Warrant Certificate or Certificates,
registered in the name of the undersigned, representing a number of Warrants at
least equal to the number of Exercised Warrants [and payment of the Exercise
Price as provided in Section 2.01(b) of the Index Warrant Agreement].

            2. This Exercise Notice [is] [is not] a Conditional Exercise Notice.
[We hereby acknowledge that a Conditional Exercise Notice will be void and of no
effect (and shall be disregarded for all purposes under the Index Warrant
Agreement) if the Spot Index on the date that, but for the provisions of Section
2.02(b) of the Index Warrant Agreement, would be the Valuation Date for the
Warrants is more than [__________] [above] [below] the Spot Index on the
Exercise Date (or, if the Exercise Date is not an Index Country Business Day, on
the immediately preceding Index Country Business Day).]

            3. We hereby acknowledge that this Exercise Notice[, the Exercise
Price] and the Definitive Warrant Certificates representing the Tendered
Warrants must be received by you by [3:00] P.M., New York City time, on a New
York Business Day in order for the Valuation Date of
<PAGE>
the Tendered Warrants to be the Index Country Business Day next succeeding such
New York Business Day, and that if this Exercise Notice[, the Exercise Price] or
such Definitive Warrant Certificates are received by you after [3:00] P.M., New
York City time, but prior to the close of business on a New York Business Day,
the Valuation Date of the Tendered Warrants shall be the Index Country Business
Day next succeeding the first New York Business Day following the day on which
this Exercise Notice[, the Exercise Price] and such Definitive Warrant
Certificates are received. [We further acknowledge that if this Conditional
Exercise Notice[, the Exercise Price] or such Definitive Warrant Certificates
are received by you after [3:00] P.M., New York City time, but prior to the
close of business on a New York Business Day, that for purposes of making the
determinations required by such Conditional Exercise Notice, the Warrants will
be deemed to be exercised on the New York Business Day next succeeding the day
on which this Exercise Notice[, the Exercise Price] and such Definitive Warrant
Certificates are received.]

            4. We hereby acknowledge that if you determine that this Exercise
Notice has not been duly completed or is not in proper form, this Exercise
Notice will be void and of no effect and will be deemed not to have been
delivered.

            5. We hereby direct you to make payment of amounts payable to us as
a result of the exercise of the Warrants hereunder as follows:

            [ ]         By cashier's check or an official bank
                        check;

or

            [ ]         By wire transfer to the following U.S.
                        dollar bank account in the United
                        States:

                        (Minimum payments of $100,000 only)

                        Bank:________________

                        Account No.:_____________

                        ABA Routing No.:___________

                                     B-2-2
<PAGE>
                        Reference:______________

            [6. We hereby certify that at the time this notice is delivered to
you, the beneficial owners of the Tendered Warrants are not Index Country
Residents.]

            Capitalized terms used herein and not defined have the meanings
assigned to them in the Index Warrant Agreement.

Dated: ________ __, 200__

                                          [NAME OF HOLDER]

                                          By:_____________________
                                             Name:
                                             Title:

                                          [Address]
                                          Telephone:
                                          Facsimile:

                                     B-2-3
<PAGE>
                                                                       EXHIBIT C

                            Form of Rejection Notice

[NAME OF DEPOSITORY PARTICIPANT OR HOLDER],
[address]
Facsimile:  ________________
Telephone:  ________________

Attention:

      Re:   Exercise of UBS AG [name of Index] Index [Put/Call] Warrants
            Expiring ________ __, 200__ (the "Warrants")

            We refer to the Index Warrant Agreement, dated as of ________ __,
200__ (the "Index Warrant Agreement"), between UBS AG (the "Corporation") and
the undersigned, as Warrant Agent (the "Warrant Agent").

            In the case of Tendered Warrants represented by a Global Warrant
Certificate and rejected pursuant to Section 2.02(c)(v) of the Index Warrant
Agreement: You are hereby notified that [the Exercise Notice delivered by you
was determined by us not to have been [duly completed] [in proper form]] [we
were not able to verify that you are a Depository Participant of [The Depository
Trust Company] in the manner, and pursuant to the procedures], as set forth in
the Index Warrant Agreement. Accordingly, we have rejected your Exercise Notice
as being unsatisfactory as to form.

            In the case of Tendered Warrants represented by a Definitive Warrant
Certificate and rejected pursuant to Section 2.02(c)(ii) of the Index Warrant
Agreement: You are hereby notified that [the Exercise Notice delivered by you
was determined by us not to have been [duly completed] [in proper form]] [the
Definitive Warrant Certificate delivered by you was determined by us not to have
been in proper form], as set forth in the Index Warrant Agreement. Accordingly,
we have rejected your Exercise Notice as being unsatisfactory as to form.

            [In the case of Tendered Warrants that become void pursuant to
Section 2.02(b) of the Index Warrant Agreement: You are hereby notified that we
have rejected your Conditional Exercise Notice because the Spot Index on the
Valuation Date was [____________], and the Spot Index
<PAGE>
on the [Designated] Exercise Date (or, if the [Designated] Exercise Date was not
an Index Country Business Day, on the immediately preceding Index Country
Business Day) was [_______________].]

            Capitalized terms used herein and not defined have the meanings
assigned to them in the Index Warrant Agreement.

Dated: ________ __, 200__

                                    [NAME OF WARRANT AGENT],
                                     as Warrant Agent

                                    By:__________________________
                                       Name:
                                       Title:

                                      C-2
<PAGE>
                                                                       EXHIBIT D

                        Form of Confirmation of Exercise

[NAME OF DEPOSITORY PARTICIPANT OR HOLDER],
[address]
Facsimile:  ________________
Telephone:  ________________

Attention:

      Re:   Exercise of UBS AG [name of Index] Index [Put/Call] Warrants
            Expiring ________ __, 200__ (the "Warrants")

            We refer to the Index Warrant Agreement, dated as of ________ __,
200__ (the "Index Warrant Agreement"), between UBS AG (the "Corporation") and
the undersigned, as Warrant Agent (the "Warrant Agent").

            We hereby confirm receipt of your Exercise Notice with respect to
____________ Warrants (the "Exercised Warrants"), and the [Definitive Warrant
Certificates representing the] Warrants relating thereto, which Exercise Notice
[and Definitive Warrant Certificates] we have found to be duly completed and in
good order[, and we have verified, in the manner provided in the Index Warrant
Agreement, that you are a Depository Participant].

            [The Corporation has elected to limit the number of Warrants that
may have an Exercise Date of ___________ __, 200__ to [____________]. Of the
Tendered Warrants, [_______________] Warrants have been selected to be Warrants
that will have an Exercise Date on such date (such Warrants, the "Exercised
Warrants"). The remaining [_____________] Tendered Warrants are deemed to be
Delayed Exercise Warrants.] [The Corporation has not elected to limit the number
of Warrants that may be exercised pursuant to Section 2.02(f) of the Index
Warrant Agreement. Accordingly, all of the Tendered Warrants will have an
Exercise Date of __________ __, 200__ and are hereinafter referred to as
"Exercised Warrants".]

            We hereby confirm that the aggregate Cash Settlement Value of
[payment currency] [_________________] of such Exercised Warrants ([payment
currency] [_____________] per Warrant) [minus the aggregate Exercise
<PAGE>
Price thereof] will be made available to you in the form of a [wire transfer]
[check], [five] New York Business Days after the Valuation Date for the
Exercised Warrants (or, if the Valuation Date for the Exercised Warrants was not
a New York Business Day, [six] New York Business Days after the Valuation Date)
in accordance with the terms of the Index Warrant Agreement.

            Capitalized terms used herein and not defined have the meanings
assigned to them in the Index Warrant Agreement.

Dated: ________ __, 200__

                                    [NAME OF WARRANT AGENT],
                                     as Warrant Agent

                                    By:__________________________
                                       Name:
                                       Title:

                                      D-2
<PAGE>
                                                                     EXHIBIT E-1

                   Form of Depository Participant Certificate

[NAME OF WARRANT AGENT],
 as Warrant Agent
[address]
Facsimile:  ________________
Telephone:  ________________

Attention:

      Re:   Automatic Exercise of UBS AG [name of Index] Index [Put/Call]
            Warrants Expiring ________ __, 200__ (the "Warrants")

            We refer to the Index Warrant Agreement, dated as of ________ __,
200__ (the "Index Warrant Agreement"), between UBS AG (the "Corporation") and
[Name of Warrant Agent], as Warrant Agent (the "Warrant Agent").

            We hereby certify that:

                  (a) we are acting on behalf of the Owners of ____________
            Warrants, which have been automatically exercised pursuant to the
            Index Warrant Agreement and which we have delivered free on the
            records of the Depository to the Warrant Account[; and

                  (b) we have received certification from such Owners that the
            beneficial owners of such Warrants are not Index Country Residents].
<PAGE>
            Capitalized terms used herein and not defined have the meanings
assigned to them in the Index Warrant Agreement.

Dated: ________ __, 200__

                                          [NAME OF DEPOSITORY
                                           PARTICIPANT]
                                          [Participant Number]

                                          By:_____________________
                                             Name:
                                             Title:

                                             [Address]
                                             Telephone:
                                             Facsimile:

                                     E-1-2
<PAGE>
                                                                     EXHIBIT E-2

                           Form of Holder Certificate

[NAME OF WARRANT AGENT],
 as Warrant Agent
[address]
Facsimile:  ________________
Telephone:  ________________

Attention:

      Re:   Automatic Exercise of UBS AG [name of Index] Index [Put/Call]
            Warrants Expiring ________ __, 200__ (the "Warrants")

            We refer to the Index Warrant Agreement, dated as of ________ __,
200__ (the "Index Warrant Agreement"), between UBS AG (the "Corporation") and
[Name of Warrant Agent], as Warrant Agent (the "Warrant Agent").

            We hereby certify that:

            (a) we are the Holders of ____________ Warrants, which have been
      automatically exercised pursuant to the Index Warrant Agreement; [and]

            (b) we have surrendered the Definitive Warrant Certificates
      representing such Warrants at the Warrant Agent Office[; and

            (c) as of the date hereof, the beneficial owners of such Warrants
      are not Index Country Residents].
<PAGE>
            Capitalized terms used herein and not defined have the meanings
assigned to them in the Index Warrant Agreement.

Dated: ________ __, 200__

                                          [NAME OF HOLDER]

                                          By:_____________________
                                             Name:
                                             Title:

                                             [Address]
                                             Telephone:
                                             Facsimile:

                                     E-2-2<PAGE>
                                                                     Exhibit 4.5

                                     UBS AG

                                       TO

                      U.S. BANK TRUST NATIONAL ASSOCIATION
                                     Trustee

                                WARRANT INDENTURE

                            Dated as of July 22, 2004

<PAGE>

                                TABLE OF CONTENTS
<TABLE>
<CAPTION>
                                                                                                PAGE
                                                                                                ----

<S>                   <C>                                                                       <C>
NOTE:  This table of contents shall not, for any purpose, be deemed to be a part of this Indenture

PARTIES............................................................................................1
RECITALS OF THE COMPANY............................................................................1
</TABLE>

                                   ARTICLE ONE

             DEFINITIONS AND OTHER PROVISIONS OF GENERAL APPLICATION
<TABLE>
<S>                   <C>                                                                       <C>
SECTION 101.          Definitions..................................................................1
                      Act..........................................................................2
                      Additional Amounts...........................................................2
                      Affiliate....................................................................2
                      Applicable Procedures........................................................2
                      Authenticating Agent.........................................................2
                      Authorized Agent.............................................................2
                      Authorized Officer...........................................................2
                      Board of Directors...........................................................3
                      Board Resolution.............................................................3
                      Business Day.................................................................3
                      Call Warrants................................................................3
                      Commission...................................................................3
                      Company......................................................................3
                      Company Request, Company Order...............................................3
                      Convert, converted, conversion...............................................3
                      Corporate Trust Office.......................................................3
                      corporation..................................................................4
                      Depositary...................................................................4
                      Event of Default.............................................................4
                      Exchange Act.................................................................4
                      Expiration Date..............................................................4
                      Final Date...................................................................4
                      Global Security..............................................................4
                      Group Executive Board........................................................4
                      Holder.......................................................................4
                      Indenture....................................................................4
                      Investment Company Act.......................................................4
                      Notice of Default............................................................4
                      Officers' Certificate........................................................4
                      Opinion of Counsel...........................................................5
                      Outstanding..................................................................5
                      Paying Agent.................................................................6
</TABLE>

                                      -i-

<PAGE>
<TABLE>
<S>                   <C>                                                                       <C>
                      Payment or Settlement Date...................................................6
                      Person.......................................................................6
                      Place of Payment.............................................................6
                      Predecessor Security.........................................................6
                      Put Warrants.................................................................6
                      Redemption Date..............................................................6
                      Redemption Price.............................................................6
                      Securities...................................................................6
                      Securities Act...............................................................6
                      Security Register............................................................6
                      Subsidiary...................................................................6
                      Trust Indenture Act..........................................................7
                      Trustee......................................................................7
                      Vice President...............................................................7
                      Warrants, Universal Warrants.................................................7
                      Warrant Property.............................................................7
SECTION 102.          Compliance Certificates and Opinions.........................................7
SECTION 103.          Form of Documents Delivered to Trustee.......................................8
SECTION 104.          Acts of Holders; Record Dates................................................9
SECTION 105.          Notices, Etc., to Trustee and Company.......................................11
SECTION 106.          Notice to Holders; Waiver...................................................11
SECTION 107.          Conflict with Trust Indenture Act...........................................12
SECTION 108.          Effect of Headings and Table of Contents....................................12
SECTION 109.          Successors and Assigns......................................................12
SECTION 110.          Separability Clause.........................................................12
SECTION 111.          Benefits of Indenture.......................................................12
SECTION 112.          Characterization of Warrants................................................12
SECTION 113.          Governing Law...............................................................13
SECTION 114.          Submission to Jurisdiction; Appointment of Agent
                      for Service of Process......................................................13
SECTION 115.          Legal Holidays..............................................................13
</TABLE>

                                   ARTICLE TWO

                                 SECURITY FORMS
<TABLE>
<S>                   <C>                                                                       <C>
SECTION 201.          Forms Generally.............................................................14
SECTION 202.          Form of Face of Call Warrant................................................14
SECTION 203.          Form of Reverse of Call Warrant.............................................18
SECTION 204.          Form of Face of Put Warrant.................................................24
SECTION 205.          Form of Reverse of Put Warrant..............................................27
SECTION 206.          Form of Legend for Global Securities........................................33
SECTION 207.          Form of Trustee's Certificate of Authentication.............................33
</TABLE>

                                      -ii-

<PAGE>

                                  ARTICLE THREE

                                 THE SECURITIES
<TABLE>
<S>                   <C>                                                                       <C>
SECTION 301.          Amount Unlimited; Issuable in Series........................................33
SECTION 302.          Denominations...............................................................37
SECTION 303.          Execution, Authentication, Delivery and Dating..............................37
SECTION 304.          Temporary Securities........................................................38
SECTION 305.          Registration, Registration of Transfer and Exchange.........................39
SECTION 306.          Mutilated, Destroyed, Lost and Stolen Securities............................41
SECTION 307.          Persons Deemed Owners.......................................................42
SECTION 308.          Cancellation................................................................42
SECTION 309.          CUSIP Numbers...............................................................43
SECTION 310.          Calculation Agent...........................................................43
</TABLE>

                                  ARTICLE FOUR

                           SATISFACTION AND DISCHARGE
<TABLE>
<S>                   <C>                                                                       <C>
SECTION 401.          Satisfaction and Discharge of Indenture.....................................43
SECTION 402.          Application of Trust Money and Warrant Property.............................45
</TABLE>

                                  ARTICLE FIVE

                                    REMEDIES
<TABLE>
<S>                   <C>                                                                       <C>
SECTION 501.          Events of Default...........................................................45
SECTION 502.          Collection of Amounts Due and Suits for Enforcement by Trustee..............46
SECTION 503.          Trustee May File Proofs of Claim............................................47
SECTION 504.          Trustee May Enforce Claims Without Possession of Securities.................47
SECTION 505.          Application of Money Collected..............................................47
SECTION 506.          Limitation on Suits.........................................................48
SECTION 507.          Unconditional Right of Holders to Receive Money or Warrant Property Due
                      With Respect to Securities and to Exercise..................................49
SECTION 508.          Restoration of Rights and Remedies..........................................49
SECTION 509.          Rights and Remedies Cumulative..............................................49
SECTION 510.          Delay or Omission Not Waiver................................................49
SECTION 511.          Control by Holders..........................................................49
SECTION 512.          Waiver of Past Defaults.....................................................50
SECTION 513.          Undertaking for Costs.......................................................50
SECTION 514.          Waiver of Usury, Stay or Extension Laws.....................................50
</TABLE>

                                   ARTICLE SIX

                                   THE TRUSTEE
<TABLE>
<S>                   <C>                                                                       <C>
SECTION 601.          Certain Duties and Responsibilities.........................................51
</TABLE>

                                     -iii-

<PAGE>

<TABLE>
<S>                   <C>                                                                       <C>
SECTION 602.          Notice of Defaults..........................................................51
SECTION 603.          Certain Rights of Trustee...................................................51
SECTION 604.          Not Responsible for Recitals or Issuance of Securities......................53
SECTION 605.          May Hold Securities.........................................................53
SECTION 606.          Money or Warrant Property Held in Trust.....................................53
SECTION 607.          Compensation and Reimbursement..............................................53
SECTION 608.          Conflicting Interests.......................................................54
SECTION 609.          Corporate Trustee Required; Eligibility.....................................54
SECTION 610.          Resignation and Removal; Appointment of Successor...........................55
SECTION 611.          Acceptance of Appointment by Successor......................................56
SECTION 612.          Merger, Conversion, Consolidation or Succession to Business.................57
SECTION 613.          Preferential Collection of Claims Against Company...........................58
SECTION 614.          Appointment of Authenticating Agent.........................................58
</TABLE>

                                  ARTICLE SEVEN

                HOLDERS' LISTS AND REPORTS BY TRUSTEE AND COMPANY
<TABLE>
<S>                   <C>                                                                       <C>
SECTION 701.          Company to Furnish Trustee Names and Addresses of Holders...................60
SECTION 702.          Preservation of Information; Communications to Holders......................60
SECTION 703.          Reports by Trustee..........................................................61
SECTION 704.          Reports by Company..........................................................61
</TABLE>

                                  ARTICLE EIGHT

              CONSOLIDATION, MERGER, CONVEYANCE, TRANSFER OR LEASE
<TABLE>
<S>                   <C>                                                                       <C>
SECTION 801.          Company May Consolidate, Etc., Only on Certain Terms........................61
SECTION 802.          Successor Substituted.......................................................62
</TABLE>

                                  ARTICLE NINE

                             SUPPLEMENTAL INDENTURES
<TABLE>
<S>                   <C>                                                                       <C>
SECTION 901.          Supplemental Indentures Without Consent of Holders..........................63
SECTION 902.          Supplemental Indentures With Consent of Holders.............................64
SECTION 903.          Execution of Supplemental Indentures........................................65
SECTION 904.          Effect of Supplemental Indentures...........................................66
SECTION 905.          Conformity with Trust Indenture Act.........................................66
SECTION 906.          Reference in Securities to Supplemental Indentures..........................66
</TABLE>

                                   ARTICLE TEN

                                    COVENANTS
<TABLE>
<S>                   <C>                                                                       <C>
SECTION 1001.         Payment or Delivery of Money or Warrant Property............................66
SECTION 1002.         Maintenance of Office or Agency.............................................66
</TABLE>

                                      -iv-

<PAGE>

<TABLE>
<S>                   <C>                                                                       <C>
SECTION 1003.         Money and Warrant Property for Securities Payments and Deliveries to Be
                      Held in Trust...............................................................67
SECTION 1004.         Statement by Officers as to Default.........................................68
SECTION 1005.         Existence...................................................................68
SECTION 1006.         Payment of Taxes and Other Claims...........................................69
SECTION 1007.         Payment of Additional Amounts...............................................69
SECTION 1008.         Waiver of Certain Covenants.................................................70
</TABLE>

                                 ARTICLE ELEVEN

                            REDEMPTION OF SECURITIES
<TABLE>
<S>                   <C>                                                                       <C>
SECTION 1101.         Applicability of Article....................................................71
SECTION 1102.         Election to Redeem; Notice to Trustee.......................................71
SECTION 1103.         Selection by Trustee of Securities to Be Redeemed...........................71
SECTION 1104.         Notice of Redemption........................................................72
SECTION 1105.         Deposit of Redemption Price.................................................73
SECTION 1106.         Securities Payable on Redemption Date.......................................73
SECTION 1107.         Securities Redeemed in Part.................................................73
</TABLE>

                                      -v-

<PAGE>

                 CERTAIN SECTIONS OF THIS INDENTURE RELATING TO
                            SECTIONS 310 THROUGH 318,
                 INCLUSIVE, OF THE TRUST INDENTURE ACT OF 1939:

<Table>
<Caption>
TRUST INDENTURE
ACT SECTION                                                 INDENTURE SECTION
                                                            -----------------
<S>                                                         <C>
Section 310 (a)(1)......................................         609
            (a)(2)......................................         609
            (a)(3)......................................         Not Applicable
            (a)(4)......................................         Not Applicable
            (b).........................................         608
                                                                 610
Section 311 (a).........................................         613
            (b).........................................         613
Section 312 (a).........................................         701
                                                                 702
            (b).........................................         702
            (c).........................................         702
Section 313 (a).........................................         703
            (b).........................................         703
            (c).........................................         703
            (d).........................................         703
Section 314 (a).........................................         704
            (a)(4)......................................         101
                                                                 1004
            (b).........................................         Not Applicable
            (c)(1)......................................         102
            (c)(2)......................................         102
            (c)(3)......................................         Not Applicable
            (d).........................................         Not Applicable
            (e).........................................         102
Section 315 (a).........................................         601
            (b).........................................         602
            (c).........................................         601
            (d).........................................         601
            (e).........................................         513
Section 316 (a).........................................         101
            (a)(1)(A)...................................         511
            (a)(1)(B)...................................         512
            (a)(2)......................................         Not Applicable
            (b).........................................         507
            (c).........................................         104
Section 317 (a)(1)......................................         502
            (a)(2)......................................         503
            (b).........................................         1003
Section 318 (a).........................................         107
</Table>

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

                                      -vi-
<PAGE>
            WARRANT INDENTURE, dated as of July 22, 2004, between UBS AG, a
corporation duly organized and existing under the laws of Switzerland (herein
called the "Company"), having its principal office at Bahnhofstrasse 45, Zurich,
Switzerland, and U.S. BANK TRUST NATIONAL ASSOCIATION, as Trustee (herein called
the "Trustee").

                             RECITALS OF THE COMPANY

            The Company has duly authorized the execution and delivery of this
Indenture to provide for the issuance from time to time of its Universal
Warrants, as hereinafter defined (herein sometimes called the "Securities"), to
be issued in one or more series as in this Indenture provided.

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

                   NOW, THEREFORE, THIS INDENTURE WITNESSETH:

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

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

            (3) all accounting terms not otherwise defined herein have the
            meanings assigned to them in accordance with generally accepted
            accounting principles and, except as otherwise herein expressly
            provided, the term "generally accepted accounting principles" with
            respect to any computation required or permitted hereunder shall
            mean such accounting principles as are generally accepted--at the
            date of such computation;
<PAGE>
            (4) unless the context otherwise requires, any reference to an
            "Article" or a "Section" refers to an Article or a Section, as the
            case may be, of this Indenture;

            (5) 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; and

            (6) when used with respect to any Security, the words "exercise" and
            "exercised" are intended to refer to the right of the Holder or the
            Company to exercise such Security and to receive in exchange money,
            securities or other property in accordance with such terms as may
            hereafter be specified for such Security as contemplated by Section
            301, and these words are not intended to refer to any right of the
            Holder or the Company to exchange such Security for other Securities
            of the same series and like tenor pursuant to Section 304, 305, 306
            or 906 or another similar provision of this Indenture, unless the
            context otherwise requires; and references herein to the terms of
            any Security that may be exercised mean such terms as may be
            specified for such Security as contemplated in Section 301.

            "Act", when used with respect to any Holder, has the meaning
specified in Section 104.

            "Additional Amounts" has the meaning specified in Section 1007.

            "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.

            "Applicable Procedures" of a Depositary means, with respect to any
matter at any time, the policies and procedures of such Depositary, if any, that
are applicable to such matter at such time.

            "Authenticating Agent" means any Person authorized by the Trustee
pursuant to Section 614 to act on behalf of the Trustee to authenticate
Securities of one or more series.

            "Authorized Agent" has the meaning specified in Section 114.

            "Authorized Officer" means an officer having the title of Chief
Financial Officer, Managing Director, Executive Director or Director of the
Company.

                                      -2-
<PAGE>
            "Board of Directors" means either the board of directors of the
Company or any duly authorized committee of that board or the Group Executive
Board.

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

            "Business Day", when used with respect to any Place of Payment,
except as may otherwise be provided in the form of Securities of any particular
series, means each Monday, Tuesday, Wednesday, Thursday and Friday which is not
a day on which banking institutions in that Place of Payment are authorized or
obligated by law or executive order to close.

            "Call Warrants" has the meaning specified in Section 301(5).

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

            "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 signed in the name of the Company by any two Authorized Officers, and
delivered to the Trustee from time to time.

            "Convert", "converted" and "conversion," when used with respect to
any Security, are intended to refer to the right of the Holder or the Company to
convert or exchange such security into or for Securities or other property in
accordance with such terms, if any, as may hereafter be specified for such
Security as contemplated by Section 301, and these words are not intended to
refer to any right of the holder or the Company to exchange such Security for
other Securities of the same series and like tenor pursuant to Section 304, 305,
306, 906 or 1107 or another similar provision of this Indenture, unless the
context otherwise requires; and references herein to the terms of any Security
that may be converted mean such terms as may be specified for such Security as
contemplated in Section 301.

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

                                      -3-
<PAGE>
            "corporation" means a corporation, association, company, joint-stock
company or business trust.

            "Depositary" means, with respect to Securities of any series
issuable in whole or in part in the form of one or more Global Securities, a
clearing agency registered under the Exchange Act that is designated to act as
Depositary for such Securities as contemplated by Section 301.

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

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

            "Expiration Date", when used with respect to Securities of any
series, means the date on which the right to exercise the Securities of such
series shall expire.

            "Final Date" has the meaning specified in Section 104.

            "Global Security" means a Security that evidences all or part of the
Securities of any series and bears the legend set forth in Section 206 (or such
legend as may be specified as contemplated by Section 301 for such Securities).

            "Group Executive Board" means the most senior executive body of the
Company, including the Chief Executive Officer and the Chief Financial Officer.

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

            "Indenture" means this instrument as originally executed and as it
may from time to time be supplemented or amended by one or more indentures
supplemental hereto entered into pursuant to the applicable provisions hereof,
including, for all purposes of this instrument and any such supplemental
indenture, the provisions of the Trust Indenture Act that are deemed to be a
part of and govern this instrument and any such supplemental indenture,
respectively. The term "Indenture" shall also include the terms of particular
series of Securities established as contemplated by Section 301.

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

            "Notice of Default" means a written notice of the kind specified in
Section 501(2).

            "Officers' Certificate" means a certificate signed by any two
Authorized Officers of the Company and delivered to the Trustee. One of the
officers signing an Officers' Certificate given pursuant to Section 1004 shall
be the principal executive, financial or accounting officer of the Company.

                                      -4-
<PAGE>
            "Opinion of Counsel" means a written opinion of counsel, who may be
counsel for the Company, and who shall be acceptable to the Trustee.

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

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

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

            (3) Securities 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 proof satisfactory to it that such
            Securities are held by a bona fide purchaser in whose hands such
            Securities are valid obligations of the Company; and

            (4) Securities as to which any money or Warrant Property payable or
            deliverable upon exercise thereof has been paid or delivered (or
            such payment or delivery has been duly provided for), or as to which
            any other particular conditions have been satisfied, in each case as
            may be provided for such Securities as contemplated in Section 301;

provided, however, that in determining whether the Holders of the requisite
number of Outstanding Warrants have given, made or taken any request, demand,
authorization, direction, notice, consent, waiver or other action hereunder as
of any date, Securities owned by the Company or any other obligor upon the
Securities or any Affiliate of the Company or of such other obligor shall be
disregarded and deemed not to be Outstanding, except that, in determining
whether the Trustee shall be protected in relying upon any such request, demand,
authorization, direction, notice, consent, waiver or other action, only
Securities which the Trustee knows to be so owned shall be so disregarded.
Securities so owned which have been pledged in good faith may be regarded as
Outstanding if the pledgee establishes to the satisfaction of the Trustee the
pledgee's right so to act with respect to such Securities and that the pledgee
is not the Company or any other obligor upon the Securities or any Affiliate of
the Company or of such other obligor.

                                      -5-
<PAGE>
            "Paying Agent", when used with respect to the Securities of any
series, means any Person authorized by the Company to pay or deliver any money
or Warrant Property payable or deliverable on behalf of the Company upon
exercise or redemption of such Securities and includes any warrant agent
appointed by the Company with respect to such series.

            "Payment or Settlement Date", when used with respect to any
Security, means the date when any money or Warrant Property with respect to such
Security becomes payable or deliverable upon exercise or redemption of such
Security in accordance with its terms.

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

            "Place of Payment", when used with respect to the Securities of any
series and subject to Section 1002, means the place or places where any money or
Warrant Property payable or deliverable upon exercise or redemption of such
Securities is payable or deliverable.

            "Predecessor Security" of any particular Security means every
previous Security evidencing all or a portion of the same contractual obligation
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 contractual obligation as the mutilated,
destroyed, lost or stolen Security.

            "Put Warrants" has the meaning specified in Section 301(5).

            "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.

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

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

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

            "Subsidiary" means any Person a majority of the combined voting
power of the total outstanding ownership interests in which is, at the time of
determination,

                                      -6-
<PAGE>
beneficially owned or held, directly or indirectly, by the Company or by one or
more other Subsidiaries, or by the Company and one or more other Subsidiaries.
For the purposes of this definition, "voting power" means power to vote in an
ordinary election of directors (or, in the case of a Person that is not a
corporation, ordinarily to appoint or approve the appointment of Persons holding
similar positions), whether at all times or only so long as no senior class of
ownership interests has such voting power by reason of any contingency.

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

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

            "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".

            "Warrants" or "Universal Warrants" means warrants, issued by the
Company and authenticated and delivered under this Indenture, to purchase or
sell, or whose cash value is determined by reference to or is linked to the
performance, level or value of, one or more of the following: (i) securities of
one or more issuers, including the common or preferred stock or other securities
of the Company or debt or equity securities of third parties, (ii) one or more
currencies, (iii) one or more commodities, (iv) any other financial, economic or
other measure or instrument (including the occurrence or non-occurrence of any
event or circumstance) and/or (v) one or more indices or baskets of the items
described in clauses (i), (ii), (iii) and (iv).

            "Warrant Property", when used with respect to a Security, means the
property described in clauses (i), (ii), (iii) and (iv) of the definition of
Warrants.

            SECTION 102. Compliance Certificates and Opinions.

            Upon any application or request by the Company to the Trustee to
take any action under any provision of this Indenture, the Company shall furnish
to the Trustee such certificates and opinions as may be required under the Trust
Indenture Act; provided, however, that no such opinion shall be required in
connection with the issuance of Securities of any Series. Each such certificate
or opinion shall be given in the form of an Officers' Certificate, if to be
given by an officer of the Company, or an Opinion of

                                      -7-
<PAGE>
Counsel, if to be given by counsel, and shall comply with the requirements of
the Trust Indenture Act and any other requirements set forth in this Indenture.

            Every certificate or opinion with respect to compliance with a
condition or covenant provided for in this Indenture (except for certificates
provided for in Section 1004) shall include,

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

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

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

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

            SECTION 103. Form of Documents Delivered to Trustee.

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

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

                                      -8-
<PAGE>
            Where any Person is required to make, give or execute two or more
applications, requests, consents, certificates, statements, opinions or other
instruments under this Indenture, they may, but need not, be consolidated and
form one instrument.

            SECTION 104. Acts of Holders; Record Dates.

            Any request, demand, authorization, direction, notice, consent,
waiver or other action provided or permitted by this Indenture to be given, made
or taken by Holders may be embodied in and evidenced by one or more instruments
of substantially similar tenor signed by such Holders in person or by agent duly
appointed in writing; and, except as herein otherwise expressly provided, such
action shall become effective when such instrument or instruments are delivered
to the Trustee and, where it is hereby expressly required, to the Company. Such
instrument or instruments (and the action embodied therein and evidenced
thereby) are herein sometimes referred to as the "Act" of the Holders signing
such instrument or instruments. Proof of execution of any such instrument or of
a writing appointing any such agent shall be sufficient for any purpose of this
Indenture and (subject to Section 601) conclusive in favor of the Trustee and
the Company, if made in the manner provided in this Section.

            The fact and date of the execution by any Person of any such
instrument or writing may be proved by the affidavit of a witness of such
execution or by a certificate of a notary public or other officer authorized by
law to take acknowledgments of deeds, certifying that the individual signing
such instrument or writing acknowledged to him 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.

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

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

            The Company may set any day as a record date for the purpose of
determining the Holders of Outstanding Securities of any series entitled to
give, make or take any request, demand, authorization, direction, notice,
consent, waiver or other action provided or permitted by this Indenture to be
given, made or taken by Holders of Securities of such series, provided that the
Company may not set a record date for, and the provisions of this paragraph
shall not apply with respect to, the giving or making of any notice,
declaration, request or direction referred to in the next paragraph. If any
record date is set pursuant to this paragraph, the Holders of Outstanding
Securities of the

                                      -9-
<PAGE>
relevant series on such record date, and no other Holders, shall be entitled to
take the relevant action, whether or not such Holders remain Holders after such
record date; provided that no such action shall be effective hereunder unless
taken on or prior to the applicable Final Date by Holders of the requisite
number of Outstanding Warrants of such series on such record date. Nothing in
this paragraph shall be construed to prevent the Company from setting a new
record date for any action for which a record date has previously been set
pursuant to this paragraph (whereupon the record date previously set shall
automatically and with no action by any Person be cancelled and of no effect),
and nothing in this paragraph shall be construed to render ineffective any
action taken by Holders of the requisite number of Outstanding Warrants of the
relevant series on the date such action is taken. Promptly after any record date
is set pursuant to this paragraph, the Company, at its own expense, shall cause
notice of such record date, the proposed action by Holders and the applicable
Final Date to be given to the Trustee in writing and to each Holder of
Securities of the relevant series in the manner set forth in Section 106.

            The Trustee may set any day as a record date for the purpose of
determining the Holders of Outstanding Securities of any series entitled to join
in the giving or making of (i) any Notice of Default, (ii) any request to
institute proceedings referred to in Section 506(2) or (iii) any direction
referred to in Section 511, in each case with respect to Securities of such
series. If any record date is set pursuant to this paragraph, the Holders of
Outstanding Securities of such series on such record date, and no other Holders,
shall be entitled to join in such notice, declaration, request or direction,
whether or not such Holders remain Holders after such record date; provided that
no such action shall be effective hereunder unless taken on or prior to the
applicable Final Date by Holders of the requisite number of Outstanding Warrants
of such series on such record date. Nothing in this paragraph shall be construed
to prevent the Trustee from setting a new record date for any action for which a
record date has previously been set pursuant to this paragraph (whereupon the
record date previously set shall automatically and with no action by any Person
be cancelled and of no effect), and nothing in this paragraph shall be construed
to render ineffective any action taken by Holders of the requisite number of
Outstanding Warrants of the relevant series on the date such action is taken.
Promptly after any record date is set pursuant to this paragraph, the Trustee,
at the Company's expense, shall cause notice of such record date, the proposed
action by Holders and the applicable Final Date to be given to the Company in
writing and to each Holder of Securities of the relevant series in the manner
set forth in Section 106.

            With respect to any record date set pursuant to this Section, the
party hereto that sets such record dates may designate any day as the "Final
Date" and from time to time may change the Final Date to any earlier or later
day; provided that no such change shall be effective unless notice of the
proposed new Final Date is given to the other party hereto in writing, and to
each Holder of Securities of the relevant series in the manner set forth in
Section 106, on or prior to the existing Final Date. If a Final Date is not
designated with respect to any record date set pursuant to this Section, the
party hereto that set such record date shall be deemed to have initially
designated the 180th day after such record date as the Final Date with respect
thereto, subject to its right to change

                                      -10-
<PAGE>
the Final Date as provided in this paragraph. Notwithstanding the foregoing, no
Final Date shall be later than the 180th day after the applicable record date.

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

            SECTION 105. Notices, Etc., to Trustee and Company.

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

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

            (2) the Company by the Trustee or by any Holder shall be sufficient
            for every purpose hereunder (unless otherwise herein expressly
            provided) if in writing and mailed, first-class postage prepaid, to
            the Company addressed to it at UBS AG, Structured Derivative
            Products, 677 Washington Blvd., Stamford, CT, 06901, Attn: Mark
            Ritter, with a copy to Legal and External Affairs, 677 Washington
            Blvd., Stamford, CT, 06901, Attn: Equities Group, or at any other
            address previously furnished in writing to the Trustee by the
            Company.

            SECTION 106. Notice to Holders; Waiver.

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

            In case by reason of the suspension of regular mail service or by
reason of any other cause it shall be impracticable to give such notice by mail,
then such

                                      -11-
<PAGE>
notification as shall be made with the approval of the Trustee shall constitute
a sufficient notification for every purpose hereunder.

            Where this Indenture provides for Notice of any event to a Holder of
a Global Security, such notice shall be sufficiently given if given to the
Depositary for such Security (or its designee), pursuant to its Applicable
Procedures, not later than the latest date (if any), and not earlier than the
earliest date (if any), prescribed for the giving of such notice.

            SECTION 107. Conflict with Trust Indenture Act.

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

            SECTION 108. 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 109. Successors and Assigns.

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

            SECTION 110. Separability Clause.

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

            SECTION 111. Benefits of Indenture.

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

            SECTION 112. Characterization of Warrants.

            By executing this Indenture, the Company intends that the
characterization, for accounting and other purposes, of the Universal Warrants
as indebtedness or debt for borrowed money, or as any other type of obligation
which is not indebtedness or debt for borrowed money, shall not be affected
solely by the fact that the

                                      -12-
<PAGE>
Universal Warrants have been issued under an indenture, as opposed to any other
instrument, or solely as a result of any of the terms and definitions used
hereunder with respect to Universal Warrants.

            SECTION 113. Governing Law.

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

            SECTION 114. Submission to Jurisdiction; Appointment of Agent for
Service of Process.

            The Company hereby appoints Robert C. Dinerstein, acting through its
office at 299 Park Avenue, New York, New York 10171 (or such other address in
the Borough of Manhattan, The City of New York, as such agent shall furnish in
writing to the Trustee) as its authorized agent (the "Authorized Agent") upon
which process may be served in any legal action or proceeding against it with
respect to its obligations under this Indenture or the Securities of any series,
as the case may be, instituted in any federal or state court in the Borough of
Manhattan, The City of New York by the Holder of any Security, and agrees that
service of process upon the Authorized Agent, together with written notice of
said service mailed or delivered to the Company, addressed as provided in
Section 105, shall be deemed in every respect effective service of process upon
the Company in any such legal action or proceeding, and the Company hereby
irrevocably submits to the non-exclusive jurisdiction of any such court in
respect of any such legal action or proceeding and waives, to the extent it may
effectively do so, any objection it may have to the laying of the venue of any
such legal action or proceeding. Such appointment shall be irrevocable so long
as the Holders of Securities shall have any rights pursuant to the terms of the
Securities or of this Indenture until the appointment of a successor Authorized
Agent by the Company and such successor's acceptance of such appointment. The
Company reserves the right to appoint another person located, or with an office,
in the Borough of Manhattan, The City of New York, selected in its sole
discretion, as a successor Authorized Agent, and upon acceptance of such
appointment by such a successor the appointment of the prior Authorized Agent
shall terminate. If for any reason the Robert C. Dinerstein ceases to be able to
act as the Authorized Agent or to have an address in the Borough of Manhattan,
The City of New York, the Company will appoint a successor Authorized Agent in
accordance with the preceding sentence. The Company further agrees to take any
and all action, including the filing of any and all documents and instruments as
may be necessary to continue such designation and appointment of such agent or
successor in full force and effect for as long as required hereunder.

            SECTION 115. Legal Holidays.

            In any case where the Payment or Settlement Date or Redemption Date
of any Security, or any date on which a Holder of any Security has the right to
exercise such Security, shall not be a Business Day at any Place of Payment,
then (notwithstanding any

                                      -13-
<PAGE>
other provision of this Indenture or of the Securities (other than a provision
of any Security which specifically states that such provision shall apply in
lieu of this Section)) payment or delivery of any money or Warrant Property
payable or deliverable with respect to such Security, or exercise of such
Security, need not be made at such Place of Payment on such date, but may be
made on the next succeeding Business Day at such Place of Payment with the same
force and effect as if made on the Payment or Settlement Date or Redemption
Date, or on such date for exercise, as the case may be.

                                  ARTICLE TWO

                                 SECURITY FORMS

            SECTION 201. Forms Generally.

            The Securities of each series shall be in substantially the form set
forth in this Article, or in such other form as shall be established by or
pursuant to a Board Resolution or in one or more indentures supplemental hereto,
in each case with such appropriate insertions, omissions, substitutions and
other variations as are required or permitted by this Indenture, and may have
such letters, numbers or other marks of identification and such legends or
endorsements placed thereon as may be required to comply with the rules of any
securities exchange or Depositary therefor or as may, consistently herewith, be
determined by the officers executing such Securities, as evidenced by their
execution thereof. If the form of Securities of any series is established by
action taken pursuant to a Board Resolution, a copy of an appropriate record of
such action shall be certified by the Secretary or an Assistant Secretary of the
Company and delivered to the Trustee at or prior to the delivery of the Company
Order contemplated by Section 303 for the authentication and delivery of such
Securities.

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

            SECTION 202. Form of Face of Call Warrant.

            [Insert any legend required by the Internal Revenue Code and the
regulations thereunder.]

            By your purchase or other acquisition of the Warrants, you will be
deemed to represent by acquiring and holding the Warrants that either (i) or
(ii) is true:

            (i) the funds that you are using to acquire the Warrants are not the
            assets of an employee benefit or other plan subject to Title I of
            the Employee Retirement Income Security Act of 1974, as amended
            ("ERISA"), a plan described in Section 4975 of the Internal Revenue
            Code of 1986, as amended (the "Code"), an entity whose underlying
            assets include "plan assets" by reason of Department of Labor
            regulation section

                                      -14-
<PAGE>
            2510.3-101 or otherwise, or a governmental plan that is subject to
            any federal, state or local law that is substantially similar to the
            provisions of Section 406 of ERISA or Section 4975 of the Code; or

            (ii) the purchase, holding and disposition of the Warrants and
            exercise of any rights related thereto will not result in a
            prohibited transaction under Section 406 of ERISA or Section 4975 of
            the Code (or in the case of a governmental plan, any federal, state
            or local provision that is substantially similar to Section 406 of
            ERISA or Section 4975 of the Code).

                                      -15-
<PAGE>
                                     UBS AG

No.________                                      CUSIP No.________________

NUMBER OF WARRANTS EVIDENCED BY THIS CERTIFICATE: [If Security is a Global
Security, insert-- UP TO]

WARRANT PROPERTY:

AMOUNT OF WARRANT PROPERTY
PURCHASABLE PER WARRANT:

EXERCISE PRICE PER WARRANT:

FORM OF PAYMENT OF
EXERCISE PRICE:

FORM OF SETTLEMENT:

DATES OF EXERCISE:

OTHER TERMS:

         This certificate certifies that , or registered assigns, is the Holder
of the number of [Designation of Universal Warrants][If Security is not a Global
Security, insert -- specified above] [If Security is a Global Security, insert
-- specified on Schedule A hereto]. Upon receipt by the Trustee of this
certificate, the exercise notice on the reverse hereof (or an exercise notice in
substantially identical form delivered herewith) (the "Exercise Notice"), duly
completed and executed, and the Exercise Price per Warrant set forth above, in
the form set forth above, for each Warrant to be exercised (the "Exercise
Property") at the Place of Payment, each Warrant evidenced hereby entitles the
Holder hereof to receive, subject to the terms and conditions set forth herein
and in the Indenture referred to below, from UBS AG, a corporation duly
organized and existing under the laws of Switzerland (herein called the
"Company", which term includes any successor Person under the Indenture), the
amount and form of property (the "Warrant Property") or money specified above.
Warrants will not entitle the Holders thereof to any of the rights of the
holders of any of the Warrant Property.

         Any payments of money due on this Security will be made at the office
or agency of the Company maintained for that purpose in New York, New York, in
such coin or currency of the United States of America as at the time of payment
is legal tender for payment of public and private debts, against surrender of
this Security in the case of any payment due on the Payment or Settlement Date;
provided that if this Security is a Global Security, payment may be made
pursuant to the Applicable Procedures of the Depositary as permitted in said
Indenture.

                                      -16-
<PAGE>
         Reference is hereby made to the further provisions of this Security set
forth on the reverse hereof, which further provisions shall for all purposes
have the same effect as if set forth at this place.

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

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

Dated:____________

                                     UBS AG

                                     By __________________________

                                            By _________________________

                                      -17-
<PAGE>
         SECTION 203. Form of Reverse of Call Warrant.

         [This Security is one of a duly authorized issue of securities of the
Company (herein called the "Securities"), issued and to be issued in one or more
series under an Indenture, dated as of July 22, 2004 (herein called the
"Indenture", which term shall have the meaning assigned to it in such
instrument), between the Company and [Trustee] (herein called the "Trustee",
which term includes any successor trustee under the Indenture), and reference is
hereby made to the Indenture for a statement of the respective rights,
limitations of rights, duties and immunities thereunder of the Company, the
Trustee and the Holders of the Securities and of the terms upon which the
Securities are, and are to be, authenticated and delivered. This Security is one
of the series designated on the face hereof [if applicable, insert -- , limited
in number to Warrants].

         [If applicable, insert-- The Securities of this series are subject to
redemption upon not less than days' nor more than days' notice, at any time [if
applicable, insert-- on or after ............, 20..], as a whole or in part, at
the election of the Company, at the following redemption prices:]

         The Warrants are unsecured contractual obligations of the Company and
rank pari passu with the Company's other unsecured contractual obligations and
with the Company's unsecured and unsubordinated debt.

         Subject to the provisions hereof and the Indenture, all or any of the
Warrants evidenced by this certificate [may be exercised on any of the dates of
exercise set forth on the face hereof by delivering or causing to be delivered
this Security (in accordance with the Applicable Procedures of the Depositary,
if this Security is a Global Security), the Exercise Notice, duly completed and
executed, and the Exercise Property for each such Warrant to the Corporate Trust
Office, in the Borough of Manhattan, The City of New York, which is, on the date
hereof [________________], or at such other address as the Trustee may specify
from time to time, with a copy of the Exercise Notice, duly completed and
executed, to the Calculation Agent,                              ,
Attention:

         Each Warrant entitles the Holder thereof to receive, upon exercise, the
Warrant Property or money set forth on the face hereof.][shall be automatically
exercised or expire worthless on the Expiration Date.

         If the Warrants are automatically exercised on the Expiration Date,
each Holder shall receive in respect thereof, on the fifth Business Day
following the Expiration Date, a payment in an amount equal to the Cash
Settlement Amount in respect of any Warrants to the extent of such Holder's
interest therein.]

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

                                      -18-
<PAGE>
         The Indenture permits, with certain exceptions as therein provided, the
amendment thereof and the modification of the rights and obligations of the
Company and the rights of the Holders of the Securities of each series to be
affected under the Indenture at any time by the Company and the Trustee with the
consent of the Holders of a majority in number of the Warrants at the time
Outstanding of all series to be affected (considered together as one class for
this purpose). The Indenture also contains provisions (i) permitting the Holders
of a majority in number of the Warrants at the time Outstanding of all series to
be affected under the Indenture (considered together as one class for this
purpose), on behalf of the Holders of all Warrants of such series, to waive
compliance by the Company with certain provisions of the Indenture and (ii)
permitting the Holders of a majority in number of the Warrants at the time
Outstanding of any series to be affected under the Indenture (with each such
series considered separately for this purpose), on behalf of the Holders of all
Warrants of such series, to waive certain past defaults under the Indenture and
their consequences. Any such consent or waiver by the Holder of this Security
shall be conclusive and binding upon such Holder and upon all future Holders of
this Security and of any Security issued upon the registration of transfer
hereof or in exchange herefor or in lieu hereof, whether or not notation of such
consent or waiver is made upon this Security.

         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 or deliver the money or Warrant Property
due with respect to this Security at the time and place herein prescribed.

         As provided in the Indenture and subject to certain limitations therein
set forth, the transfer of this Security is registrable in the Security
Register, upon surrender of this Security for registration of transfer at the
office or agency of the Company in any Place of Payment with respect to this
Security, duly endorsed by, or accompanied by a written instrument of transfer
in form satisfactory to the Company and the Security Registrar duly executed by,
the Holder hereof or his attorney duly authorized in writing, and thereupon one
or more new Securities of this series and of like tenor, of authorized
denominations and for the same number of Warrants, will be issued to the
designated transferee or transferees.

         The Securities of this series are issuable only in registered form in
denominations of _______ Warrants and any multiple thereof. As provided in the
Indenture and subject to certain limitations therein set forth, Securities of
this series are exchangeable for a like number of Warrants of this series and of
like tenor of a different authorized denomination, as requested by the Holder
surrendering the same.

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

                                      -19-
<PAGE>
         Prior to due presentment of this Security for registration of transfer,
the Company, the Trustee and any agent of the Company or the Trustee may treat
the Person in whose name this Security is registered as the owner hereof for all
purposes, whether or not any payment or delivery of money or Warrant Property
with respect to this Security be overdue, and neither the Company, the Trustee
nor any such agent shall be affected by notice to the contrary.

         This Security is a Global Security and is subject to the provisions of
the Indenture relating to Global Securities, including the limitations in
Section 305 thereof on transfers and exchanges of Global Securities.

         This Security and the Indenture shall be governed by and construed in
accordance with the laws 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.

                                      -20-
<PAGE>
                       [Designation of Universal Warrants]

                                 Exercise Notice

[Trustee]
[address]
Attn:           [name]                    Tel.:     [number]
                [name]                    Tel.:     [number]
                Fax:                                [number]

with a copy to:

[Insert name and address of Calculation Agent]
Attn:                                     Tel.:
                                          Tel.:

                Fax:

Re:        Call Warrants on        expiring        , 20    , issued by UBS AG
           and described in the prospectus supplement dated            to the
           prospectus dated            , 20  .

Ladies and Gentlemen:

         The undersigned is, or is acting on behalf of, the beneficial owner of
such number of the Warrants referenced above as is specified at the end of this
Exercise Notice. The undersigned hereby irrevocably elects to exercise such
number of Warrants. The exercise is to be effective on the Business Day on which
the Trustee has received this Exercise Notice, together with all other items
required to be delivered on exercise, and the Calculation Agent has received a
copy of this Exercise Notice, unless all required items have not been received
by 11:00 A.M., New York City time, on that Business Day, in which case the
exercise will be effective as of the next Business Day. We understand, however,
that no exercise shall be effective unless it is effective, as provided above,
no later than the Business Day before the Expiration Date. The effective date
will be the exercise notice date.

         If the Warrants to be exercised are in global form, the undersigned is
delivering this exercise notice to the Trustee and to the Calculation Agent, in
each case by facsimile transmission to the relevant number stated above, or such
other number as the Trustee or Calculation Agent may have designated for this
purpose to the Holder. [If applicable, insert -- In addition, the cash amount
equal to the strike value times the number of Warrants indicated below and the
beneficial interest in the number of Warrants indicated below are being
transferred on the books of the Depositary to an account of the Trustee at the
Depositary.]

                                      -21-
<PAGE>
         If the Warrants to be exercised are not in global form, the undersigned
or the beneficial owner is the Holder of the Warrants and is delivering this
Exercise Notice to the Trustee and to the Calculation Agent by facsimile
transmission as described above. [If applicable, insert -- In addition, the cash
amount equal to the strike value times the number of Warrants indicated below
and the certificate representing the Warrant are being delivered to the
Trustee.]

         If the undersigned is not the beneficial owner of the Warrant to be
exercised, the undersigned hereby represents that it has been duly authorized by
the beneficial owner to act on behalf of the beneficial owner.

         Terms used and not defined in this notice have the meanings given to
them in the Warrant or the Indenture specified in the Warrant. The exercise of
the Warrant will be governed by the terms of the Warrant and the Indenture.

         The Calculation Agent should note receipt of the copy of this Exercise
Notice, in the place provided below, on the Business Day of receipt, noting the
date and time of receipt. The consideration to be delivered or paid in the
requested exercise should be made on the [fifth] Business Day after the exercise
notice date in accordance with the terms of the Warrant.

Number of Warrants to be exercised:

(must be a number greater than or equal to )

Means of Payment of Settlement Value:.

                                         Very truly yours,

                                            (Name of beneficial owner or Person
                                              authorized to act on its behalf)
                                         (Title)

                                                      (Telephone No.)
                                                         (Fax No.)

Receipt of the above exercise notice is hereby noted:

, as Calculation Agent

By:  ____________________________
       (Title)

Date and time of receipt:

(Date)

(Time)

                                      -22-
<PAGE>
[If Security is a Global Security, insert this Schedule A.]

                                   SCHEDULE A
                       [DESIGNATION OF UNIVERSAL WARRANTS]

                                     GLOBAL
                                UNIVERSAL WARRANT
                       SCHEDULE OF EXCHANGES OR EXERCISES

         The initial number of Universal Warrants represented by this Global

         Security is In accordance with the Indenture dated as of
................., 20.., as amended or supplemented, between the Company and
[Trustee], as Trustee, the following (A) exchanges of [the number of Universal
Warrants previously represented hereby and indicated below for a like number of
Universal Warrants represented by a Global Security that has been separated from
a Unit (a "Separated Universal Warrant")](1) [the number of Universal Warrants
previously represented by a Global Security that is part of a Unit (an "Attached
Unit Universal Warrant") and indicated below for a like number of Universal
Warrants represented by this Global Security](2) or (B) reductions in the number
of Universal Warrants represented hereby as a result of the exercise of the
number of such Warrants indicated below have been made:

<TABLE>
<CAPTION>
   Date of          [Number          Reduced        [Number of      [Increased      Number of       Reduced      Notation Made
  Exchange          Exchanged         Number      Attached Unit       Number        Universal        Number         by or on
or Exercise            for         Outstanding      Universal      Outstanding      Warrants      Outstanding      Behalf of
                    Separated     Following Such     Warrants     Following Such    Exercised    Following Such     Trustee
                    Universal      Exchange](1)   Exchanged for    Exchange](2)                     Exercise
                   Warrants](1)                     Universal
                                                     Warrants
                                                   represented
                                                     by this
                                                    Separated
                                                    Universal
                                                   Warrant](2)
<S>                <C>            <C>             <C>             <C>               <C>          <C>             <C>

</TABLE>

----------
(1)    Applies only if this Global Security is part of a Unit.
(2)    Applies only if this Global Security has been separated from a Unit.

                                      -23-
<PAGE>
         SECTION 204. Form of Face of Put Warrant.

         [Insert any legend required by the Internal Revenue Code and the
regulations thereunder.]

         By your purchase or other acquisition of the Warrants, you will be
deemed to represent by acquiring and holding the Warrants that either (i) or
(ii) is true:

         (i) the funds that you are using to acquire the Warrants are not the
         assets of an employee benefit or other plan subject to Title I of the
         Employee Retirement Income Security Act of 1974, as amended ("ERISA"),
         a plan described in Section 4975 of the Internal Revenue Code of 1986,
         as amended (the "Code"), an entity whose underlying assets include
         "plan assets" by reason of Department of Labor regulation section
         2510.3-101 or otherwise, or a governmental plan that is subject to any
         federal, state or local law that is substantially similar to the
         provisions of Section 406 of ERISA or Section 4975 of the Code; or

         (ii) the purchase, holding and disposition of the Warrants and exercise
         of any rights related thereto will not result in a prohibited
         transaction under Section 406 of ERISA or Section 4975 of the Code (or
         in the case of a governmental plan, any federal, state or local
         provision that is substantially similar to Section 406 of ERISA or
         Section 4975 of the Code).

                                      -24-
<PAGE>
                                     UBS AG

No __________                                    CUSIP No._________________

         NUMBER OF WARRANTS EVIDENCED BY THIS CERTIFICATE: [If Security is a
Global Security, insert-- UP TO]

CASH SETTLEMENT VALUE PER WARRANT
(OR METHOD OF DETERMINING SAME):

WARRANT PROPERTY:

AMOUNT OF WARRANT PROPERTY DELIVERABLE BY HOLDER UPON EXERCISE PER WARRANT:

PUT PRICE FOR SUCH SPECIFIED AMOUNT OF WARRANT PROPERTY PER WARRANT:

METHOD OF DELIVERY OF ANY WARRANT PROPERTY TO BE DELIVERED FOR SALE UPON
EXERCISE OF WARRANTS:

DATES OF EXERCISE:

OTHER TERMS:

         This certificate certifies that , or registered assigns, is the Holder
of the number of [Designation of Universal Warrants] [If Security is not a
Global Security, insert -- specified above] [If Security is a Global Security,
insert -- specified on Schedule A hereto]. Upon receipt by the Trustee of this
certificate, the exercise notice on the reverse hereof (or an exercise notice in
substantially identical form delivered herewith) (the "Exercise Notice"), duly
completed and executed, and the amount, if any, of Warrant Property saleable per
Warrant set forth above, adjusted, if applicable, as set forth above, for each
Warrant to be exercised, delivered as set forth above at the Place of Payment,
each Warrant evidenced hereby entitles the Holder hereof to receive, subject to
the terms and conditions set forth herein and in the Indenture referred to
below, from UBS AG, a corporation duly organized and existing under the laws of
Switzerland (herein called the "Company", which term includes any successor
Person under the Indenture), the [Cash Settlement Value][Put Price] per Warrant
specified above.

         Unless otherwise indicated above, a Warrant will not require or entitle
a Holder thereof to sell or deliver to the Company, nor will the Company be
under any obligation to, nor will it, purchase or take delivery from any Holder
of, any Warrant Property, and upon exercise of a Warrant, the Company will make
only a cash payment in the amount of the [Cash Settlement Value][Put Price] per
Warrant. Holders of Warrants will not receive any interest on any [Cash
Settlement Value][Put Price].

                                      -25-
<PAGE>
         Any payments of money due on this Security will be made at the office
or agency of the Company maintained for that purpose in New York, New York, in
such coin or currency of the United States of America as at the time of payment
is legal tender for payment of public and private debts, against surrender of
this Security in the case of any payment due on the Payment or Settlement Date;
provided that if this Security is a Global Security, payment may be made
pursuant to the Applicable Procedures of the Depositary as permitted in said
Indenture.

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

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

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

Dated:______________________

                                       UBS AG

                                       By ____________________
                                       By ____________________

                                      -26-
<PAGE>
         SECTION 205. Form of Reverse of Put Warrant.

         This Security is one of a duly authorized issue of securities of the
Company (herein called the "Securities"), issued and to be issued in one or more
series under an Indenture, dated as of July 22, 2004 (herein called the
"Indenture", which term shall have the meaning assigned to it in such
instrument), between the Company and [Trustee], as Trustee (herein called the
"Trustee", which term includes any successor trustee under the Indenture), and
reference is hereby made to the Indenture for a statement of the respective
rights, limitations of rights, duties and immunities thereunder of the Company,
the Trustee and the Holders of the Securities and of the terms upon which the
Securities are, and are to be, authenticated and delivered. This Security is one
of the series designated on the face hereof [If applicable, insert -- , limited
in number to ____________ Warrants].

         [If applicable, insert-- The Securities of this series are subject to
redemption upon not less than days' nor more than days' notice, at any time [if
applicable, insert-- on or after ............, 20..], as a whole or in part, at
the election of the Company, at the following redemption prices:]

         The Warrants are unsecured contractual obligations of the Company and
rank pari passu with the Company's other unsecured contractual obligations and
with the Company's unsecured and unsubordinated debt.

         Subject to the provisions hereof and the Indenture, all or any of the
Warrants evidenced by this certificate [may be exercised on any of the dates of
exercise set forth on the face hereof by delivering or causing to be delivered
this Security (in accordance with the Applicable Procedures of the Depositary,
if this Security is a Global Security), the Exercise Notice, duly completed and
executed, and, if specified on the face hereof, the Exercise Property for each
such Warrant to the Corporate Trust Office, in the Borough of Manhattan, The
City of New York, which is, on the date hereof (unless otherwise specified
herein), [___________________________], or at such other address as the Trustee
may specify from time to time, with a copy to the Calculation Agent, _________,
Attention: __________________________.

         Each Warrant entitles the Holder thereof to receive, upon exercise, the
money set forth on the face hereof.][shall be automatically exercised or expire
worthless on the Expiration Date.

         If the Warrants are automatically exercised on the Expiration Date,
each Holder shall receive in respect thereof, on the fifth Business Day
following the Expiration Date, a payment in an amount equal to the Cash
Settlement Amount in respect of any Warrants to the extent of such Holder's
interest therein.]

                                      -27-
<PAGE>
         [If the Security is subject to redemption of any kind, insert -- In the
event of redemption of this Security in part only, a new Security or Securities
of this series for the unredeemed portion hereof will be issued in the name of
the Holder hereof upon the cancellation hereof.]

         The Indenture permits, with certain exceptions as therein provided, the
amendment thereof and the modification of the rights and obligations of the
Company and the rights of the Holders of the Securities of each series to be
affected under the Indenture at any time by the Company and the Trustee with the
consent of the Holders of a majority in number of the Warrants at the time
Outstanding of all series to be affected (considered together as one class for
this purpose). The Indenture also contains provisions (i) permitting the Holders
of a majority in number of the Warrants at the time Outstanding of all series to
be affected under the Indenture (considered together as one class for this
purpose), on behalf of the Holders of all Warrants of such series, to waive
compliance by the Company with certain provisions of the Indenture and (ii)
permitting the Holders of a majority in number of the Warrants at the time
Outstanding of any series to be affected under the Indenture (with each such
series considered separately for this purpose), on behalf of the Holders of all
Warrants of such series, to waive certain past defaults under the Indenture and
their consequences. Any such consent or waiver by the Holder of this Security
shall be conclusive and binding upon such Holder and upon all future Holders of
this Security and of any Security issued upon the registration of transfer
hereof or in exchange herefor or in lieu hereof, whether or not notation of such
consent or waiver is made upon this Security.

         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 or deliver the money or Warrant Property
due with respect to this Security at the time and place herein prescribed.

         As provided in the Indenture and subject to certain limitations therein
set forth, the transfer of this Security is registrable in the Security
Register, upon surrender of this Security for registration of transfer at the
office or agency of the Company in any Place of Payment with respect to this
Security, duly endorsed by, or accompanied by a written instrument of transfer
in form satisfactory to the Company and the Security Registrar duly executed by,
the Holder hereof or his attorney duly authorized in writing, and thereupon one
or more new Securities of this series and of like tenor, of authorized
denominations and for the same number of Warrants, will be issued to the
designated transferee or transferees.

         The Securities of this series are issuable only in registered form in
denominations of . Warrants and any multiple thereof. As provided in the
Indenture and subject to certain limitations therein set forth, Securities of
this series are exchangeable for a like number of Warrants of this series and of
like tenor of a different authorized denomination, as requested by the Holder
surrendering the same.

                                      -28-
<PAGE>
         No service charge shall be made for any such registration of transfer
or exchange, but the Company may require payment of a sum sufficient to cover
any tax or other governmental charge payable in connection therewith.

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

         This Security is a Global Security and is subject to the provisions of
the Indenture relating to Global Securities, including the limitations in
Section 305 thereof on transfers and exchanges of Global Securities.

         This Security and the Indenture shall be governed by and construed in
accordance with the laws 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.

                                      -29-
<PAGE>
                       [Designation of Universal Warrants]

                                 Exercise Notice

[Trustee]
[address]
Attn:           [name]                    Tel.:     [number]
                [name]                    Tel.:     [number]
                Fax:                                [number]

with a copy to:

[Insert name and address of Calculation Agent]
Attn:                                     Tel.:
                                          Tel.:
                                          Fax:

Re:        Put Warrants on         expiring           , 20  , issued by UBS AG
           and described in the prospectus supplement dated           to the
           prospectus dated          , 20  .

Ladies and Gentlemen:

         The undersigned is, or is acting on behalf of, the beneficial owner of
such number of the Warrants referenced above as is specified at the end of this
Exercise Notice. The undersigned hereby irrevocably elects to exercise such
number of the Warrants. The exercise is to be effective on the Business Day on
which the Trustee has received this Exercise Notice, together with all other
items required to be delivered on exercise, and the Calculation Agent has
received a copy of this Exercise Notice, unless all required items have not been
received by 11:00 A.M., New York City time, on that Business Day, in which case
the exercise will be effective as of the next Business Day. We understand,
however, that no exercise shall be effective unless it is effective, as provided
above, no later than the Business Day before the Expiration Date. The effective
date will be the exercise notice date.

         If the Warrants to be exercised are in global form, the undersigned is
delivering this Exercise Notice to the Trustee and to the Calculation Agent, in
each case by facsimile transmission to the relevant number stated above, or such
other number as the Trustee or Calculation Agent may have designated for this
purpose to the Holder. In addition, the beneficial interest in the number of
Warrants indicated below is being transferred on the books of the Depositary to
an account of the Trustee at the Depositary.

         If the Warrants to be exercised are not in global form, the undersigned
or the beneficial owner is the Holder of the Warrants and is delivering this
Exercise Notice to the Trustee and to the Calculation Agent by facsimile
transmission as described above. In addition, the certificate representing the
Warrants is being delivered to the Trustee.

                                      -30-
<PAGE>
         If the undersigned is not the beneficial owner of the Warrant to be
exercised, the undersigned hereby represents that it has been duly authorized by
the beneficial owner to act on behalf of the beneficial owner.

         Terms used and not defined in this notice have the meanings given to
them in the Warrant or the Indenture specified in the Warrant. The exercise of
the Warrant will be governed by the terms of the Warrant and the Indenture.

         The calculation agent should note receipt of the copy of this exercise
notice, in the place provided below, on the business day of receipt, noting the
date and time of receipt. The consideration to be delivered or paid in the
requested exercise should be made on the        business day after the exercise
notice date in accordance with the terms of the warrant.

Number of Warrants to be exercised:

(must be a number greater than or equal to )

Means of Payment of [Cash Settlement Value][Put Price]:

                                         Very truly yours,

                                            (Name of beneficial owner or Person
                                              authorized to act on its behalf)
                                        (Title)
                                                      (Telephone No.)
                                                         (Fax No.)

Receipt of the above exercise notice is hereby noted:

, as Calculation Agent

By:  ____________________________
       (Title)

Date and time of receipt:

(Date)

(Time)

                                      -31-
<PAGE>
[If Security is a Global Security, insert this Schedule A.]

                       [DESIGNATION OF UNIVERSAL WARRANTS]

                                   SCHEDULE A

                                     GLOBAL
                                UNIVERSAL WARRANT
                       SCHEDULE OF EXCHANGES OR EXERCISES

         The initial number of Universal Warrants represented by this Global
Security is In accordance with the Indenture, dated as of _____________, 20__,
between the Company and [Trustee], as Trustee, [If applicable, insert-- and the
Unit Agreement, dated as of............, 20.., between the Company and
[Trustee], as Unit Agent, the following (A) exchanges of [the number of
Universal Warrants previously represented hereby and indicated below for a like
number of Universal Warrants represented by a Global Security that has been
separated from a Unit (a "Separated Universal Warrant")](1) [the number of
Universal Warrants previously represented by a Global Security that is part of a
Unit (an "Attached Unit Universal Warrant") and indicated below for a like
number of Universal Warrants represented by this Global Security](2) or (B)
reductions in the number of Universal Warrants represented hereby as a result of
the exercise of the number of such Warrants indicated below have been made:

<TABLE>
<CAPTION>
   Date of           [Number         Reduced        [Number of      [Increased      Number of       Reduced      Notation Made
   Exchange         Exchanged         Number      Attached Unit       Number        Universal        Number          by or
 or Exercise           for         Outstanding      Universal      Outstanding      Warrants      Outstanding      on Behalf
                    Separated     Following Such     Warrants     Following Such    Exercised    Following Such    of Trustee
                    Universal      Exchange](1)   Exchanged for    Exchange](2)                     Exercise
                   Warrants](1)                     Universal
                                                     Warrants
                                                   represented
                                                     by this
                                                    Separated
                                                    Universal
                                                   Warrant](2)
<S>                <C>            <C>              <C>            <C>               <C>          <C>             <C>

</TABLE>

----------
(1) Applies only if this Global Security is part of a Unit.

(2) Applies only if this Global Security has been separated from a Unit.

                                      -32-
<PAGE>
         SECTION 206. Form of Legend for Global Securities.

         Unless otherwise specified as contemplated by Section 301 for the
Securities evidenced thereby, every Global Security authenticated and delivered
hereunder shall bear a legend in substantially the following form:

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

         SECTION 207. Form of Trustee's Certificate of Authentication.

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

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

Dated:_________________

                                           U.S. Bank Trust National Association,
                                                       As Trustee

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

                                  ARTICLE THREE

                                 THE SECURITIES

         SECTION 301. Amount Unlimited; Issuable in Series.

         The aggregate number of Warrants which may be authenticated and
delivered under this Indenture is unlimited.

         The Securities may be issued in one or more series. There shall be
established in or pursuant to corporate authorization and, subject to Section
303, set forth,

                                      -33-
<PAGE>
or determined in the manner provided, in an Officers' Certificate, or
established in one or more indentures supplemental hereto, prior to the issuance
of Securities of any series,

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

         (2) any limit upon the aggregate number of the Warrants of the series
         that may be authenticated and delivered under this Indenture (except
         for Securities authenticated and delivered upon registration of
         transfer of, or in exchange for, or in lieu of, other Securities of the
         series pursuant to Section 304, 305, 306, 906 or 1107 and except for
         any Securities which, pursuant to Section 303, are deemed never to have
         been authenticated and delivered hereunder);

         (3) the money payable or receivable or specific Warrant Property
         purchasable or deliverable by or on behalf of the Holder upon exercise
         of the Securities of the series, and the amount thereof (or the method
         for determining the same);

         (4) the price at which the Securities of the series will be issued and,
         if other than the currency of the United States of America, the
         currency, currencies, composite currency, composite currencies or
         currency units in which such issue price will be payable and the manner
         of determining the equivalent thereof in the currency of the United
         States of America for any purpose, including for purposes of the
         definition of "Outstanding" in Section 101;

         (5) whether the Securities of the series are warrants to purchase the
         Warrant Property (including warrants that may be settled by means of
         net cash settlement or cashless exercise) ("Call Warrants"), warrants
         to sell the Warrant Property (including warrants that may be settled by
         means of net cash settlement or cashless exercise) ("Put Warrants") or
         any other type of warrants;

         (6) the price at which and, if other than the currency of the United
         States of America, the currency, currencies, composite currency,
         composite currencies or currency units with which, the Warrant Property
         may be purchased or sold by or on behalf of the Holder upon exercise of
         the Securities of the series (or the method for determining the same);

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

                                      -34-
<PAGE>
         (8) whether the exercise price for the Securities of the series may be
         paid in cash or by the exchange of any such Securities or other
         securities of the Company, or both, or otherwise, whether such exercise
         price may be netted against any money or Warrant Property payable or
         deliverable by the Company with respect to such Securities and the
         method of exercise of such Securities;

         (9) if the Securities of the series are call warrants, whether the
         exercise of such Securities is to be settled by payment in cash or
         delivery of the Warrant Property by the Company or both or otherwise,
         and whether the election of such form of settlement is to be at the
         option of the Holder or of the Company;

         (10) if the Securities of the series are put warrants, whether the
         exercise of such Securities is to be settled by payment in cash or
         delivery of the Warrant Property by the Holder or both, or otherwise,
         and whether the election of such form of settlement is to be at the
         option of the Holder or of the Company;

         (11) the date on which the right to exercise the Securities of the
         series shall commence and the Expiration Date of the series or, if the
         Securities of the series are not continuously exercisable throughout
         such period, the specific date or dates on which they will be
         exercisable;

         (12) if applicable, that any Securities of the series shall be issuable
         in whole or in part in the form of one or more Global Securities and,
         in such case, the respective Depositaries for such Global Securities,
         the form of any legend or legends which shall be borne by any such
         Global Security in addition to or in lieu of that set forth in Section
         206, and any circumstances in addition to or in lieu of those set forth
         in Clause (2) of the last paragraph of Section 305 in which any such
         Global Security may be exchanged in whole or in part for Securities
         registered, and any transfer of such Global Security in whole or in
         part may be registered, in the name or names of Persons other than the
         Depositary for such Global Security or a nominee thereof and any other
         provisions governing exchanges or transfers of any such Global
         Security;

         (13) any warrant agents, Depositaries, Paying Agents, transfer agents
         or registrars or any determination agents, Calculation Agents or other
         agents with respect to Securities of the series;

         (14) whether the Securities of the series will be issued separately or
         together as a unit (a "Unit") with one or more other securities of the
         Company or any other person and, if the Securities of the series are to
         be issued as components of Units, whether and on what terms the
         Securities

                                      -35-
<PAGE>
         of the series may be separated from the other components of such Units
         prior to the Expiration Date of such Securities;

         (15) if other than denominations of 100 Warrants and any multiple
         thereof, the denominations in which any Securities of the series shall
         be issuable;

         (16) the Place of Payment with respect to Securities of the series, if
         other than the Corporate Trust Office;

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

         (18) any provisions necessary to permit or facilitate the issuance,
         payment or exercise of any Securities of the series that may be
         exercised for securities or other property other than Securities of the
         same series and of like tenor, whether in addition to, or in lieu of,
         any payment of money or delivery of other property and whether at the
         option of the Company or otherwise;

         (19) any addition to, elimination of or other change in the Events of
         Default which applies to Securities of the series, including making
         Events of Default inapplicable or changing the remedies available to
         Holders of the Securities of the series upon an Event of Default; and

         (20) if applicable, that Additional Amounts, pursuant to Section 1007,
         will not be payable by the Company in respect of the Securities of the
         series; and

         (21) any other terms of the series (which terms shall not be
         inconsistent with the provisions of this Indenture, except as permitted
         by Section 901(5)).

         All Securities of any one series shall be substantially identical
except as to denomination and except as may otherwise be provided in or pursuant
to the Board Resolution referred to above and (subject to Section 303) set
forth, or determined in the manner provided, in the Officers' Certificate
referred to above or in any such indenture supplemental hereto.

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

                                      -36-

<PAGE>
            The Securities are unsecured contractual obligations of the Company
and rank pari passu with the Company's other unsecured contractual obligations
and with the Company's unsecured and unsubordinated debt.

            No Security shall entitle the Holder or any beneficial owner thereof
to any of the rights of a holder or beneficial owner of Warrant Property,
including the right to receive the payment of any dividends on, principal of, or
premium or interest on Warrant Property or to vote or to enforce any rights
under any documents governing Warrant Property.

            SECTION 302. Denominations.

            The Securities of each series shall be issuable only in registered
form without coupons and only in such denominations as shall be specified as
contemplated by Section 301. In the absence of any such specified denomination
with respect to the Securities of any series, the Securities of such series
shall be issuable in denominations of 100 Warrants and any multiple thereof.

            SECTION 303. Execution, Authentication, Delivery and Dating.

            The Securities shall be executed on behalf of the Company by any two
Authorized Officers. The signature of any of these officers on the Securities
may be manual or facsimile.

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

            At any time and from time to time after the execution and delivery
of this Indenture, the Company may deliver Securities of any series executed by
the Company to the Trustee for authentication, together with a Company Order for
the authentication and delivery of such Securities, and the Trustee in
accordance with the Company Order shall authenticate and deliver such
Securities. If the form or terms of the Securities of the series have been
established by or pursuant to one or more Board Resolutions as permitted by
Sections 201 and 301, in authenticating such Securities, and accepting the
additional responsibilities under this Indenture in relation to such Securities,
the Trustee shall be entitled to receive, and (subject to Section 601) shall be
fully protected in relying upon, an Opinion of Counsel stating,

            (1) if the form of such Securities has been established by or
            pursuant to Board Resolution as permitted by Section 201, that such
            form has been established in conformity with the provisions of this
            Indenture;

                                      -37-
<PAGE>
            (2) if the terms of such Securities have been established by or
            pursuant to Board Resolution as permitted by Section 301, that such
            terms have been established in conformity with the provisions of
            this Indenture; and

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

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

            Notwithstanding the provisions of Section 301 and of the preceding
paragraph, if all Securities of a series are not to be originally issued at one
time, it shall not be necessary to deliver the Officers' Certificate otherwise
required pursuant to Section 301 or the Company Order and Opinion of Counsel
otherwise required pursuant to such preceding paragraph at or prior to the
authentication of each Security of such series if such documents are delivered
at or prior to the authentication upon original issuance of the first Security
of such series to be issued.

            Each Security shall be dated the date of its authentication.

            No Security shall be entitled to any benefit under this Indenture or
be valid or obligatory for any purpose unless there appears on such Security a
certificate of authentication substantially in the form provided for herein
executed by the Trustee by manual signature, and such certificate upon any
Security shall be conclusive evidence, and the only evidence, that such Security
has been duly authenticated and delivered hereunder. Notwithstanding the
foregoing, if any Security shall have been authenticated and delivered hereunder
but never issued and sold by the Company, and the Company shall deliver such
Security to the Trustee for cancellation as provided in Section 309, for all
purposes of this Indenture such Security shall be deemed never to have been
authenticated and delivered hereunder and shall never be entitled to the
benefits of this Indenture.

            SECTION 304. Temporary Securities.

            Pending the preparation of definitive Securities of any series, the
Company may execute, and upon Company Order the Trustee shall authenticate and
deliver, temporary Securities which are printed, lithographed, typewritten,
mimeographed or otherwise produced, in any authorized denomination,
substantially of the tenor of the

                                      -38-
<PAGE>
definitive Securities in lieu of which they are issued and with such appropriate
insertions, omissions, substitutions and other variations as the officers
executing such Securities may determine, as evidenced by their execution of such
Securities.

            If temporary Securities of any series are issued, the Company will
cause definitive Securities of that series to be prepared without unreasonable
delay. After the preparation of definitive Securities of such series, the
temporary Securities of such series shall be exchangeable for definitive
Securities of such series upon surrender of the temporary Securities of such
series at the office or agency of the Company in a Place of Payment for that
series, without charge to the Holder. Upon surrender for cancellation of any one
or more temporary Securities of any series, the Company shall execute and the
Trustee shall authenticate and deliver in exchange therefor one or more
definitive Securities of the same series, of any authorized denominations and of
like tenor and aggregate number of Warrants. Until so exchanged, the temporary
Securities of any series shall in all respects be entitled to the same benefits
under this Indenture as definitive Securities of such series and tenor.

            SECTION 305. Registration, Registration of Transfer and Exchange.

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

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

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

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

                                      -39-
<PAGE>
            Every Security presented or surrendered for registration of transfer
or for exchange shall (if so required by the Company or the Trustee) be duly
endorsed, or be accompanied by a written instrument of transfer in form
satisfactory to the Company and the Security Registrar duly executed, by the
Holder thereof or 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, 906 or 1107 not involving any transfer.

            If the Securities of any series are to be redeemed in part, the
Company shall not be required (A) to issue, register the transfer of or exchange
any Securities of that series during a period beginning at the opening of
business 15 days before the day of the mailing of a notice of redemption of any
such Securities selected for redemption under Section 1103 and ending at the
close of business on the day of such mailing (or during such period as otherwise
specified as contemplated by Section 301 for such Securities), or (B) to
register the transfer of or exchange any Security so selected for redemption in
whole or in part, except the unredeemed portion of any Security being redeemed
in part.

            The provisions of Clauses (1), (2), (3), (4) and (5) below shall
apply only to Global Securities:

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

            (2) Notwithstanding any other provision in this Indenture, and
            subject to such applicable provisions, if any, as may be specified
            as contemplated by Section 301, no Global Security may be exchanged
            in whole or in part for Securities registered, and no transfer of a
            Global Security in whole or in part may be registered, in the name
            of any Person other than the Depositary for such Global Security or
            a nominee thereof unless (A) such Depositary (i) has notified the
            Company that it is unwilling or unable to continue as Depositary for
            such Global Security or (ii) has ceased to be a clearing agency
            registered under the Exchange Act, (B) there shall have occurred and
            be continuing an Event of Default with respect to such Global
            Security or (C) there shall exist such circumstances, if any, in
            addition to or in lieu of the foregoing as have been specified for
            this purpose as contemplated by Section 301.

                                      -40-
<PAGE>
            (3) Subject to Clause (2) above and to such applicable provisions,
            if any, as may be specified as contemplated by Section 301, any
            exchange of a Global Security for other Securities may be made in
            whole or in part, and all Securities issued in exchange for a Global
            Security or any portion thereof shall be registered in such names as
            the Depositary for such Global Security shall direct.

            (4) Every Security authenticated and delivered upon registration of
            transfer of, or in exchange for or in lieu of, a Global Security or
            any portion thereof, whether pursuant to this Section, Section 304,
            306, 906 or 1107 or otherwise, shall be authenticated and delivered
            in the form of, and shall be, a Global Security, unless such
            Security is registered in the name of a Person other than the
            Depositary for such Global Security or a nominee thereof.

            (5) Except for the exchange rights provided in Clause (2) above,
            owners of beneficial interest in a Global Security held on their
            behalf by a Depositary shall not be entitled to receive physical
            delivery of Securities in definitive form, shall not be considered
            the Holders thereof for any purpose under this Indenture and shall
            have no rights under this Indenture with respect to such Global
            Security, and such Depositary may be treated by the Company, the
            Trustee and any agent of any of them as the Holder and owner of such
            Global Security for all purposes whatsoever. Notwithstanding the
            foregoing, the Depositary for any Global Security may grant proxies
            and otherwise authorize any person, including the beneficial owners
            of interest in such Global Security, to take any action which a
            Holder is entitled to take under this Indenture with respect to such
            Global Security.

            In the event that upon any exercise of Warrants evidenced by a
certificate the number of Warrants exercised shall be less than the total number
of Warrants evidenced by such certificate, there shall be issued to the Holder
thereof or his assignee a new certificate evidencing the number of Warrants of
the same series and of like tenor not exercised, provided that in the case of
Warrants evidenced by one or more Global Securities, in lieu of issuing such new
certificate the Trustee shall note the cancellation of such exercised Warrants
and the number of such Warrants not exercised and remaining Outstanding by
notation on such Global Security(ies).

            SECTION 306. Mutilated, Destroyed, Lost and Stolen Securities.

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

                                      -41-
<PAGE>
            If there shall be delivered to the Company and the Trustee (i)
evidence to their satisfaction of the destruction, loss or theft of any Security
and (ii) such security or indemnity as may be required by them to save each of
them and any agent of either of them harmless, then, in the absence of notice to
the Company or the Trustee that such Security has been acquired by a bona fide
purchaser, the Company shall execute and the Trustee shall authenticate and
deliver, in lieu of any such destroyed, lost or stolen Security, a new Security
of the same series and of like tenor and number of Warrants and bearing a number
not contemporaneously outstanding.

            In case any such mutilated, destroyed, lost or stolen Security has
been or is about to be exercised, or deemed to be exercised, the Company in its
absolute discretion may, instead of issuing a new Security, direct the Trustee
to treat the same as if it had received the Security together with an
irrevocable exercise notice in proper form in respect thereof, as established
with respect to the Securities of such series.

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

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

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

            SECTION 307. Persons Deemed Owners.

            Prior to due presentment of a Security for registration of transfer,
the Company, the Trustee and any agent of the Company or the Trustee may treat
the Person in whose name such Security is registered as the owner of such
Security for the purpose of receiving payment or delivery of any money or
Warrant Property payable or deliverable with respect to such Security and for
all other purposes whatsoever, whether or not such payment or delivery with
respect to 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 308. Cancellation.

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

                                      -42-
<PAGE>
delivered to the Trustee and shall be promptly canceled by it. The Company may
at any time deliver to the Trustee for cancellation any Securities previously
authenticated and delivered hereunder which the Company may have acquired in any
manner whatsoever, and may deliver to the Trustee (or to any other Person for
delivery to the Trustee) for cancellation any Securities previously
authenticated hereunder which the Company has not issued and sold, and all
Securities so delivered shall be promptly cancelled by the Trustee. No
Securities shall be authenticated in lieu of or in exchange for any Securities
cancelled as provided in this Section, except as expressly permitted by this
Indenture. All canceled Securities held by the Trustee shall be disposed of as
directed by a Company Order.

            SECTION 309. CUSIP Numbers.

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

            SECTION 310. Calculation Agent.

            Pursuant to Section 301, the Company may, in connection with any
series of Securities, appoint UBS Securities LLC or any other person or entity
as Calculation Agent to make any calculations as may be required pursuant to the
terms of such series of Securities. Any such Calculation Agent shall act as an
independent expert, and the Company may provide that the Calculation Agent's
calculations and determinations under this Indenture shall, absent manifest
error, be final and binding on the Company, the Trustee and the Holders of the
Securities of such series.

                                  ARTICLE FOUR

                           SATISFACTION AND DISCHARGE

            SECTION 401. Satisfaction and Discharge of Indenture.

            This Indenture shall upon Company Request cease to be of further
effect (except as to any surviving rights of exercise, registration of transfer
or exchange of Securities herein expressly provided for, and the Trustee, at the
expense of the Company, shall execute without recourse, representation or
warranty of any kind, proper instruments acknowledging satisfaction and
discharge of this Indenture, when

                                      -43-
<PAGE>
            (1) either

               (A) all Securities theretofore authenticated and delivered (other
               than (i) Securities which have been destroyed, lost or stolen and
               which have been replaced, paid or settled as provided in Section
               306 and (ii) Securities for whose payment or settlement money or
               Warrant Property has theretofore been deposited in trust or
               segregated and held in trust by the Company and thereafter repaid
               or redelivered to the Company or discharged from such trust, as
               provided in Section 1003) have been delivered to the Trustee for
               cancellation; or

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

                        (i) have been exercised,

                        (ii) will be automatically exercised at their Expiration
                        Date within one year, or

                        (iii) are to be called for redemption within one year
                        under arrangements satisfactory to the Trustee for the
                        giving of notice of redemption by the Trustee in the
                        name, and at the expense, of the Company, and the
                        Company, in the case of (i), (ii) or (iii) above, has
                        deposited or caused to be deposited with the Trustee as
                        trust funds or trust property in trust for the purpose
                        money or Warrant Property in an amount sufficient to pay
                        and discharge the entire contractual obligation on such
                        Securities not theretofore delivered to the Trustee for
                        cancellation, for all amounts of money or Warrant
                        Property due with respect to such Securities to the date
                        of such deposit or to the Payment or Settlement Date or
                        Redemption Date of such Securities, as the case may be;

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

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

            Notwithstanding the satisfaction and discharge of this Indenture,
the obligations of the Company to the Trustee under Section 607, the obligations
of the Trustee to any Authenticating Agent under Section 614 and, if money or
Warrant Property shall have been deposited with the Trustee pursuant to
subclause (B) of Clause (1) of this Section, the obligations of the Trustee
under Section 402 and the last paragraph of Section 1003 shall survive.

                                      -44-
<PAGE>
            SECTION 402. Application of Trust Money and Warrant Property.

            Subject to the provisions of the last paragraph of Section 1003, all
money and Warrant Property deposited with the Trustee pursuant to Section 401
shall be held in trust and applied by it, in accordance with the provisions of
the Securities and this Indenture, to the payment or delivery, either directly
or through any Paying Agent (including the Company acting as its own Paying
Agent) as the Trustee may determine, to the Persons entitled thereto, of all
amounts of money or Warrant Property due with respect to such Securities for
whose payment or settlement such money or Warrant Property has been deposited
with the Trustee.

                                  ARTICLE FIVE

                                    REMEDIES

            SECTION 501. Events of Default.

            Except as otherwise specified as contemplated by Section 301 for
Securities of any series, "Event of Default", wherever used herein with respect
to any Security of any series, means any one of the following events (whatever
the reason for such Event of Default and whether it shall 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 or delivery of any money or Warrant
            Property in respect of such Security (but not such a default in
            respect of any other Security of that or any other series) in
            accordance with its terms;

            (2) default in the performance, or breach, of any covenant or
            warranty of the Company in this Indenture (other than a covenant or
            warranty a default in whose performance or whose breach is elsewhere
            in this Section specifically dealt with or which has expressly been
            included in this Indenture solely for the benefit of series of
            Securities other than that series), and continuance of such default
            or breach for a period of 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 10% in number
            of the Outstanding Warrants of that series a written notice
            specifying such default or breach and requiring it to be remedied
            and stating that such notice is a "Notice of Default" hereunder;

            (3) the entry by a court having jurisdiction in the premises of (A)
            a decree or order for relief in respect of the Company in an
            involuntary case or proceeding under any applicable Swiss
            bankruptcy, insolvency, reorganization or other similar law or (B) a
            decree or order appointing a custodian, receiver, liquidator,
            assignee, trustee, sequestrator or other similar official of the
            Company or of any substantial part of its property,

                                      -45-
<PAGE>
            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;

            (4) the commencement by the Company of a voluntary case or
            proceeding under any applicable Swiss bankruptcy, insolvency,
            reorganization or other similar law or of any other case or
            proceeding to be adjudicated a bankrupt or insolvent, or the consent
            by it to the entry of a decree or order for relief in respect of the
            Company in an involuntary case or proceeding under any applicable
            Swiss bankruptcy, insolvency, reorganization or other similar law or
            to the commencement of any bankruptcy or insolvency case or
            proceeding against it, or the filing by it of a petition or answer
            or consent seeking reorganization or relief under any applicable
            Swiss law, or the consent by it to the filing of such petition or to
            the appointment of or taking possession by a custodian, receiver,
            liquidator, assignee, trustee, sequestrator or other similar
            official of the Company or of any substantial part of its property,
            or the making by it of an assignment for the benefit of creditors,
            or the admission by it in writing or its inability to pay its debts
            generally as they become due, or the taking of corporate action by
            the Company in furtherance of any such action; or

            (5) any other Event of Default provided with respect to such
            Security or to Securities of that series.

            Notwithstanding any other provision of this Indenture or of any
Security, a failure by the Company to perform any obligation or otherwise
observe any covenant in any Security or in this Indenture insofar as it applies
to any Security shall not constitute a default unless all conditions precedent
to the Company's obligation to be satisfied by the Holder of such Security shall
have been satisfied.

            SECTION 502. Collection of Amounts Due and Suits for Enforcement by
Trustee.

            The Company covenants that if default is made in the payment or
delivery of any money or Warrant Property in respect of any Security in
accordance with its terms upon satisfaction by the Holder thereof of all
conditions precedent to the Company's obligation to make such payment or
delivery to be satisfied by such Holder, the Company will, upon demand of the
Trustee, pay to it, for the benefit of the Holder of such Security, the whole
amount of Warrant Property or money then due and payable on such Security and,
in addition thereto, such further amount as shall be sufficient to cover the
costs and expenses of collection, including the reasonable compensation,
expenses, disbursements and advances of the Trustee, its agents and counsel.

            If an Event of Default with respect to any Security occurs and is
continuing, the Trustee may in its discretion proceed to protect and enforce its
rights and the rights of the Holder of such Security by such appropriate
judicial proceedings as the

                                      -46-
<PAGE>
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 503. Trustee May File Proofs of Claim.

            In case of any judicial proceeding relative to the Company (or any
other obligor upon the Securities), its property or its creditors, the Trustee
shall be entitled and empowered, by intervention in such proceeding or
otherwise, to take any and all actions authorized under the Trust Indenture Act
in order to have claims of the Holders and the Trustee allowed in any such
proceeding. In particular, the Trustee shall be authorized to participate as a
member, voting or otherwise, of any official committee appointed on such matter,
to collect and receive any moneys, Warrant Property or other property payable or
deliverable on any such claims and to distribute the same; and any custodian,
receiver, assignee, trustee, liquidator, sequestrator or other similar official
in any such judicial proceeding is hereby authorized by each Holder to make such
payments to the Trustee and, in the event that the Trustee shall consent to the
making of such payments directly to the Holders, to pay to the Trustee any
amount due it for the reasonable compensation, expenses, disbursements and
advances of the Trustee, its agents and counsel, and any other amounts due the
Trustee under Section 607.

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

            SECTION 504. Trustee May Enforce Claims Without Possession of
Securities.

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

            SECTION 505. Application of Money Collected.

            Any money collected by the Trustee pursuant to this Article shall be
applied in the following order, at the date or dates fixed by the Trustee and,
in case of the distribution of such money on account of amounts due with respect
to the Securities,

                                      -47-
<PAGE>
upon presentation of the Securities and the notation thereon of the payment if
only partially paid and upon surrender thereof if fully paid:

            FIRST: To the payment of all amounts due the Trustee under Section
607;

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

            THIRD: To the Company.

            SECTION 506. Limitation on Suits.

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

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

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

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

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

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

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

                                      -48-
<PAGE>
            SECTION 507. Unconditional Right of Holders to Receive Money or
Warrant Property Due With Respect to Securities and to Exercise.

            Notwithstanding any other provision in this Indenture, the Holder of
any Security shall have the right, which is absolute and unconditional, to
receive payment or delivery of the money or Warrant Property due with respect to
such Security on the Payment or Settlement Date (or, in the case of redemption,
on the Redemption Date) of such Security and to exercise such Security in
accordance with its terms, and to institute suit for the enforcement of any such
payment or delivery and such right to exercise, and such rights shall not be
impaired without the consent of such Holder.

            SECTION 508. Restoration of Rights and Remedies.

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

            SECTION 509. Rights and Remedies Cumulative.

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

            SECTION 510. Delay or Omission Not Waiver.

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

            SECTION 511. Control by Holders.

            The Holders of a majority in number of the Outstanding Warrants of
any series shall have the right to direct the time, method and place of
conducting any

                                      -49-
<PAGE>
proceeding for any remedy available to the Trustee, or exercising
any trust or power conferred on the Trustee, with respect to the Securities of
such series, provided that

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

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

            SECTION 512. Waiver of Past Defaults.

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

            (1) in the payment or delivery of the money or Warrant Property due
            on any Security of such series or in respect of any Holder's right
            to exercise any Security, or

            (2) in respect of a covenant or provision hereof which under Article
            Nine cannot be modified or amended without the consent of the Holder
            of each Outstanding Security of such series 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 513. Undertaking for Costs.

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

            SECTION 514. Waiver of Usury, Stay or Extension Laws.

            The Company covenants (to the extent that it may lawfully do so)
that it will not at any time insist upon, or plead, or in any manner whatsoever
claim or take the benefit or advantage of, any usury, stay or extension law
wherever enacted, now or at any time hereafter in force, which may affect the
covenants or the performance of this

                                      -50-
<PAGE>
Indenture; and the Company (to the extent that it may lawfully do so) hereby
expressly waives all benefit or advantage of any such law and covenants that it
will not hinder, delay or impede the execution of any power herein granted to
the Trustee, but will suffer and permit the execution of every such power as
though no such law had been enacted.

                                  ARTICLE SIX

                                   THE TRUSTEE

            SECTION 601. Certain Duties and Responsibilities.

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

            SECTION 602. Notice of Defaults.

            If a default occurs hereunder with respect to Securities of any
series, the Trustee shall give the Holders of Securities of such series notice
of such default as and to the extent provided by the Trust Indenture Act;
provided, however, that in the case of any default of the character specified in
Section 501(2) with respect to Securities of such series, no such notice to
Holders shall be given until at least 30 days after the occurrence thereof. For
the purpose of this Section, the term "default" means any event which is, or
after notice or lapse of time or both would become, an Event of Default with
respect to Securities of such series.

            SECTION 603. Certain Rights of Trustee.

            Subject to the provisions of Section 601:

            (1) 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, warrant or other paper or document believed by it to be
            genuine and to have been signed or presented by the proper party or
            parties;

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

                                      -51-
<PAGE>
            (3) whenever in the administration of this Indenture the Trustee
            shall deem it desirable that a matter be proved or established prior
            to taking, suffering or omitting any action hereunder, the Trustee
            (unless other evidence be herein specifically prescribed) may, in
            the absence of bad faith on its part, rely upon an Officers'
            Certificate;

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

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

            (6) the Trustee shall not be bound to make any investigation into
            the facts or matters stated in any resolution, certificate,
            statement, instrument, opinion, report, notice, request, direction,
            consent, order, warrant 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;

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

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

            (9) except during the continuance of an Event of Default, the
            Trustee need perform only these duties as are specifically set forth
            in this Indenture.

            The Trustee shall not be required 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.

                                      -52-
<PAGE>
            In the event that an Event of Default has occurred and is
continuing, the Trustee shall, in the exercise of its power, use the degree of
care of a prudent person in similar circumstances in the conduct of his or her
own affairs.

            SECTION 604. Not Responsible for Recitals or Issuance of Securities.

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

            SECTION 605. May Hold Securities.

            The Trustee, any Authenticating Agent, any Paying Agent, any
Security Registrar or any other agent of the Company, in its individual or any
other capacity, may become the owner or pledgee of Securities and, subject to
Sections 608 and 613, may otherwise deal with the Company with the same rights
it would have if it were not Trustee, Authenticating Agent, Paying Agent,
Security Registrar or such other agent.

            SECTION 606. Money or Warrant Property Held in Trust.

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

            SECTION 607. Compensation and Reimbursement.

            The Company agrees

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

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

                                      -53-
<PAGE>
            (3) to indemnify the Trustee for, and to hold it harmless against,
            any loss, liability or expense incurred without negligence or bad
            faith on its part, arising out of or in connection with the
            acceptance or administration of the trust or trusts hereunder,
            including the costs and expenses of enforcing this Indenture against
            the Company (including Section 607) and defending itself against any
            claim, whether asserted by any Holder or the Company, or liability
            in connection with the exercise or performance of any of its powers
            or duties hereunder.

            To secure the Company's payment obligations in this Section 607, the
Trustee shall have a lien prior to the Securities on all money or property held
or collected by the Trustee, except that held in trust to pay the principal
amount, premium, if any, or interest, if any, as the case may be, on particular
Securities.

            The Company's payment obligations pursuant to this Section 607 shall
survive the discharge of this Indenture.

            When the Trustee incurs expenses after the occurrence of a Default
specified in Section 501(3) or (4), the expenses are intended to constitute
expenses of administration under any applicable Swiss, Federal or State
bankruptcy, insolvency or other similar law.

            SECTION 608. Conflicting Interests.

            If the Trustee has or shall acquire a conflicting interest within
the meaning of the Trust Indenture Act, the Trustee shall either eliminate such
interest or resign, to the extent and in the manner provided by, and subject to
the provisions of, the Trust Indenture Act and this Indenture. To the extent
permitted by such Act, the Trustee shall not be deemed to have a conflicting
interest by virtue of being a trustee under this Indenture with respect to
Securities of more than one series, [or a trustee under - list here any prior
indentures between the Company and the Trustee that have not been satisfied and
discharged and that may be excluded by the provisio to Section 310(b)(1) of the
Trust Indenture Act].

            SECTION 609. Corporate Trustee Required; Eligibility.

            There shall at all times be one (and only one) Trustee hereunder
with respect to the Securities of each series, which may be Trustee hereunder
for Securities of one or more other series. Each Trustee shall be a Person that
is eligible pursuant to the Trust Indenture Act to act as such, has a combined
capital and surplus of at least $50,000,000 and has its Corporate Trust Office
in the Borough of Manhattan, The City of New York. If any such Person publishes
reports of condition at least annually, pursuant to law or to the requirements
of its supervising or examining authority, then for the purposes of this Section
and to the extent permitted by the Trust Indenture Act, the combined capital and
surplus of such Person 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

                                      -54-
<PAGE>
with respect to the Securities of any series shall cease to be eligible in
accordance with the provisions of this Section, it shall resign immediately in
the manner and with the effect hereinafter specified in this Article.

            SECTION 610. Resignation and Removal; Appointment of Successor.

            No resignation or removal of the Trustee and no appointment of a
successor Trustee pursuant to this Article shall become effective until the
acceptance of appointment by the successor Trustee in accordance with the
applicable requirements of Section 611.

            The Trustee may resign at any time with respect to the Securities of
one or more series by giving written notice thereof to the Company. If the
instrument of acceptance by a successor Trustee required by Section 611 shall
not have been delivered to the Trustee within 30 days after the giving of such
notice of resignation, the resigning Trustee may petition any court of competent
jurisdiction for the appointment of a successor Trustee with respect to the
Securities of such series.

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

            If at any time:

            (1) the Trustee shall fail to comply with Section 608 after written
            request therefor by the Company or by any Holder who has been a bona
            fide Holder of a Security for at least six months, or

            (2) the Trustee shall cease to be eligible under Section 609 and
            shall fail to resign after written request therefor by the Company
            or by any such Holder, or

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

then, in any such case, (A) the Company by a Board Resolution may remove the
Trustee with respect to all Securities, or (B) subject to Section 513, any
Holder who has been a bona fide Holder of a Security for at least six months
may, on behalf of himself and all others similarly situated, petition any court
of competent jurisdiction for the removal of the Trustee with respect to all
Securities and the appointment of a successor Trustee or Trustees.

                                      -55-
<PAGE>
            If the Trustee shall resign, be removed or become incapable of
acting, or if a vacancy shall occur in the office of Trustee for any cause, with
respect to the Securities of one or more series, the Company, by a Board
Resolution, shall promptly appoint a successor Trustee or Trustees with respect
to the Securities of that or those series (it being understood that any such
successor Trustee may be appointed with respect to the Securities of one or more
or all of such series and that at any time there shall be only one Trustee with
respect to the Securities of any particular series) and shall comply with the
applicable requirements of Section 611. If, within one year after such
resignation, removal or incapability, or the occurrence of such vacancy, a
successor Trustee with respect to the Securities of any series shall be
appointed by Act of the Holders of a majority in number of the Outstanding
Warrants of such series delivered to the Company and the retiring Trustee, the
successor Trustee so appointed shall, forthwith upon its acceptance of such
appointment in accordance with the applicable requirements of Section 611,
become the successor Trustee with respect to the Securities of such series and
to that extent supersede the successor Trustee appointed by the Company. If no
successor Trustee with respect to the Securities of any series shall have been
so appointed by the Company or the Holders and accepted appointment in the
manner required by Section 611, any Holder who has been a bona fide Holder of a
Security of such series 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 with respect to the Securities of such
series.

            The Company shall give notice of each resignation and each removal
of the Trustee with respect to the Securities of any series and each appointment
of a successor Trustee with respect to the Securities of any series to all
Holders of Securities of such series in the manner provided in Section 106. Each
notice shall include the name of the successor Trustee with respect to the
Securities of such series and the address of its Corporate Trust Office.

            SECTION 611. Acceptance of Appointment by Successor.

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

            In case of the appointment hereunder of a successor Trustee with
respect to the Securities of one or more (but not all) series, the Company, the
retiring Trustee and

                                      -56-
<PAGE>
each successor Trustee with respect to the Securities of one or more series
shall execute and deliver an indenture supplemental hereto wherein each
successor Trustee shall accept such appointment and which (1) shall contain such
provisions as shall be necessary or desirable to transfer and confirm to, and to
vest in, each successor Trustee all the rights, powers, trusts and duties of the
retiring Trustee with respect to the Securities of that or those series to which
the appointment of such successor Trustee relates, (2) if the retiring Trustee
is not retiring with respect to all Securities, shall contain such provisions as
shall be deemed necessary or desirable to confirm that all the rights, powers,
trusts and duties of the retiring Trustee with respect to the Securities of that
or those series as to which the retiring Trustee is not retiring shall continue
to be vested in the retiring Trustee, and (3) shall add to or change any of the
provisions of this Indenture as shall be necessary to provide for or facilitate
the administration of the trusts hereunder by more than one Trustee, it being
understood that nothing herein or in such supplemental indenture shall
constitute such Trustees co-trustees of the same trust and that each such
Trustee shall be trustee of a trust or trusts hereunder separate and apart from
any trust or trusts hereunder administered by any other such Trustee; and upon
the execution and delivery of such supplemental indenture the resignation or
removal of the retiring Trustee shall become effective to the extent provided
therein and each such successor Trustee, without any further act, deed or
conveyance, shall become vested with all the rights, powers, trusts and duties
of the retiring Trustee with respect to the Securities of that or those series
to which the appointment of such successor Trustee relates; but, on request of
the Company or any successor Trustee, such retiring Trustee shall duly assign,
transfer and deliver to such successor Trustee all money, Warrant Property and
other property held by such retiring Trustee hereunder with respect to the
Securities of that or those series to which the appointment of such successor
Trustee relates.

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

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

            SECTION 612. 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 qualified and eligible under this Article,
without the execution or filing of any paper or any further act on the part of
any of the parties hereto. In case any Securities shall have been authenticated,
but not delivered, by the Trustee then in office, any successor by

                                      -57-
<PAGE>
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 613. Preferential Collection of Claims Against Company.

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

            SECTION 614. Appointment of Authenticating Agent.

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

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

                                      -58-
<PAGE>
            An Authenticating Agent may resign at any time by giving written
notice thereof to the Trustee and to the Company. The Trustee may at any time
terminate the agency of an Authenticating Agent by giving written notice thereof
to such Authenticating Agent and to the Company. Upon receiving such a notice of
resignation or upon such a termination, or in case at any time such
Authenticating Agent shall cease to be eligible in accordance with the
provisions of this Section, the Trustee may appoint a successor Authenticating
Agent which shall be acceptable to the Company and shall give notice of such
appointment in the manner provided in Section 106 to all Holders of Securities
of the series with respect to which such Authenticating Agent will serve. Any
successor Authenticating Agent upon acceptance of its appointment hereunder
shall become vested with all the rights, powers and duties of its predecessor
hereunder, with like effect as if originally named as an Authenticating Agent.
No successor Authenticating Agent shall be appointed unless eligible under the
provisions of this Section.

            The Trustee agrees to pay to each Authenticating Agent from time to
time reasonable compensation for its services under this Section, and the
Trustee shall be entitled to be reimbursed for such payments, subject to the
provisions of Section 607.

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

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

                                            As Trustee

                                    By      ______________________________
                                               As Authenticating Agent

                                    By      ______________________________
                                                 Authorized Officer

                                      -59-
<PAGE>
                                 ARTICLE SEVEN

                HOLDERS' LISTS AND REPORTS BY TRUSTEE AND COMPANY

      SECTION 701. Company to Furnish Trustee Names and Addresses of Holders.

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

      (1) semi-annually, not later than May 15 and November 15 in each year, a
      list, in such form as the Trustee may reasonably require, of the names and
      addresses of the Holders of Securities of each series as of the preceding
      May 1 or November 1, as the case may be, and

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

excluding from any such list names and addresses received by the Trustee in its
capacity as Security Registrar.

      SECTION 702. Preservation of Information; Communications to Holders.

      The Trustee shall preserve, in as current a form as is reasonably
practicable, the names and addresses of Holders contained in the most recent
list furnished to the Trustee as provided in Section 701 and the names and
addresses of Holders received by the Trustee in its capacity as Security
Registrar. The Trustee may destroy any list furnished to it as provided in
Section 701 upon receipt of a new list so furnished.

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

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

                                      -60-
<PAGE>
      SECTION 703. Reports by Trustee.

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

      Reports so required to be transmitted at stated intervals of not more than
12 months shall be transmitted no later than May 15 in each calendar year,
commencing in 2004.

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

      SECTION 704. Reports by Company.

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

                                 ARTICLE EIGHT

              CONSOLIDATION, MERGER, CONVEYANCE, TRANSFER OR LEASE

      SECTION 801. Company May Consolidate, Etc., Only on Certain Terms.

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

      (1) in case the Company shall consolidate with or merge into another
      Person or convey, transfer or lease its properties and assets
      substantially as an entirety to any Person, the Person formed by such
      consolidation or into which the Company is merged or the Person which
      acquires by conveyance or transfer, or which leases, the properties and
      assets of the Company substantially as an entirety shall be a corporation,
      partnership or trust, shall be organized and validly existing under the
      laws of Switzerland or any other jurisdiction, and shall expressly assume,
      by an indenture

                                      -61-
<PAGE>
      supplemental hereto, executed and delivered to the Trustee, in form
      satisfactory to the Trustee, the due and punctual payment or delivery of
      the money or Warrant Property payable or deliverable by the Company with
      respect to all the Securities in accordance with their terms and the
      performance or observance of every covenant of this Indenture on the part
      of the Company to be performed or observed and shall have provided for the
      right to exercise each Security in accordance with its terms;

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

      (3) if, as a result of any such consolidation or merger or such
      conveyance, transfer or lease, properties or assets of the Company would
      become subject to a mortgage, pledge, lien, security interest or other
      encumbrance which would not be permitted by this Indenture, the Company or
      such successor Person, as the case may be, shall take such steps as shall
      be necessary effectively to secure the Securities equally and ratably with
      (or prior to) all indebtedness or contractual obligations secured thereby;
      and

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

      SECTION 802 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
801, the successor Person formed by such consolidation or into which the Company
is merged or to which such conveyance, transfer or lease is made shall succeed
to, and be substituted for, and may exercise every right and power of, the
Company under this Indenture with the same effect as if such successor Person
had been named as the Company herein, and thereafter, except in the case of a
lease, the predecessor Person shall be relieved of all obligations and covenants
under this Indenture and the Securities.

                                      -62-
<PAGE>
                                  ARTICLE NINE

                             SUPPLEMENTAL INDENTURES

      SECTION 901. Supplemental Indentures Without Consent of Holders.

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

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

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

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

      (4) to add to or change any of the provisions of this Indenture to such
      extent as shall be necessary to permit or facilitate the issuance of
      Securities in bearer form, registrable or not registrable, or to permit or
      facilitate the issuance of Securities in uncertificated form; or

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

      (6) to secure the Securities; or

      (7) to establish the form or terms of Securities of any series as
      permitted by Sections 201 and 301; or

                                      -63-
<PAGE>
      (8) to evidence and provide for the acceptance of appointment hereunder by
      a successor Trustee with respect to the Securities of one or more series
      and to add to or change any of the provisions of this Indenture as shall
      be necessary to provide for or facilitate the administration of the trusts
      hereunder by more than one Trustee, pursuant to the requirements of
      Section 611; or

      (9) to add to or change any of the provisions of this Indenture with
      respect to any Securities that by their terms may be exercised for
      securities or other property other than Securities of the same series and
      of like tenor, in order to permit or facilitate the issuance, payment,
      settlement or exercise of such Securities; or

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

      SECTION 902. Supplemental Indentures With Consent of Holders.

      With the consent of the Holders of more than 50% in number of the
Outstanding Warrants of each series affected by such supplemental indenture, by
Act of said Holders delivered to the Company and the Trustee, the Company, when
authorized by a Board Resolution, and the Trustee may enter into an indenture or
indentures supplemental hereto for the purpose of adding any provisions to or
changing in any manner or eliminating any of the provisions of this Indenture or
of modifying in any manner the rights of the Holders of Securities of such
series under this Indenture; provided, however, that no such supplemental
indenture shall, without the consent of the Holder of each Outstanding Security
affected thereby,

      (1) change the terms of any Security with respect to the Payment or
      Settlement Date or exercise price thereof, or reduce the amount of money
      or reduce the amount or change the kind of Warrant Property payable or
      deliverable upon the exercise thereof or any premium payable upon the
      redemption thereof, or change any Place of Payment where, or the coin or
      currency in which, any Security or any money payable or deliverable upon
      the exercise thereof is payable, or permit the Company to redeem any
      Security if, absent such supplemental indenture, the Company would not be
      permitted to do so, or impair the right to institute suit for the
      enforcement of any such payment or delivery on or after the Payment or
      Settlement Date (or, in the case of redemption, on or after the Redemption
      Date) thereof, or impair the Holder's right to exercise such Security on
      the terms provided therein, or

                                      -64-
<PAGE>
      (2) if any Security provides that the Holder may require the Company to
      repurchase such Security, impair such Holder's right to require repurchase
      of such Security on the terms provided therein, or

      (3) reduce the percentage in number of the Outstanding Warrants of any one
      or more series (considered separately or together as one class, as
      applicable), the consent of whose Holders is required for any such
      supplemental indenture, or the consent of whose Holders is required for
      any waiver (of compliance with certain provisions of this Indenture or
      certain defaults hereunder and their consequences) provided for in this
      Indenture, or

      (4) modify any of the provisions of this Section, Section 512 or Section
      1008, except to increase any such percentage or to provide that certain
      other provisions of this Indenture cannot be modified or waived without
      the consent of the Holder of each Outstanding Security affected thereby;
      provided, however, that this clause shall not be deemed to require the
      consent of any Holder with respect to changes in the references to "the
      Trustee" and concomitant changes in this Section and Section 1008, or the
      deletion of this proviso, in accordance with the requirements of Sections
      611 and 901(8).

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

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

      SECTION 903. 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.

                                      -65-
<PAGE>
      SECTION 904. Effect of Supplemental Indentures.

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

      SECTION 905. Conformity with Trust Indenture Act.

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

      SECTION 906. Reference in Securities to Supplemental Indentures.

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

                                  ARTICLE TEN

                                    COVENANTS

      SECTION 1001. Payment or Delivery of Money or Warrant Property.

      The Company covenants and agrees for the benefit of each series of
Securities that it will duly and punctually pay or deliver the money or Warrant
Property payable or deliverable by the Company with respect to the Securities of
that series in accordance with the terms of the Securities and this Indenture.

      SECTION 1002. Maintenance of Office or Agency.

      Subject to the last paragraph of this section, the Company will maintain
in each Place of Payment for any series of Securities an office or agency where
Securities of that series may be presented or surrendered for payment, where
Securities of that series may be surrendered for registration of transfer or
exchange, where Securities may be surrendered upon exercise and where notices
and demands to or upon the Company in respect of the Securities of that series
and this Indenture may be served. The Company will give prompt written notice to
the Trustee of the location, and any change in the location, of such office or
agency. If at any time the Company shall fail to maintain any such required
office or agency or shall fail to furnish the Trustee with the address thereof,
such presentations, surrenders, notices and demands may be made or served at the

                                      -66-
<PAGE>
Corporate Trust Office of the Trustee, and the Company hereby appoints the
Trustee as its agent to receive all such presentations, surrenders, notices and
demands.

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

      With respect to any Global Security, and except as otherwise may be
specified for such Global Security as contemplated by Section 301, the Corporate
Trust Office of the Trustee shall be the Place of Payment where such Global
Security may be presented or surrendered for exercise, payment or delivery of
money or Warrant Property due with respect to such Security or registration of
transfer or exchange, or where successor Securities may be delivered in exchange
therefor, provided, however, that any such payment, delivery, presentation or
surrender effected pursuant to the Applicable Procedures of the Depositary for
such Global Security shall be deemed to have been effected at the Place of
Payment for such Global Security in accordance with the provisions of this
Indenture.

      SECTION 1003. Money and Warrant Property for Securities Payments and
Deliveries to Be Held in Trust.

      If the Company shall at any time act as its own Paying Agent with respect
to any series of Securities, it will, on or before the Payment or Settlement
Date of the Securities of that series, segregate and hold in trust for the
benefit of the Persons entitled thereto money or Warrant Property sufficient to
pay or deliver the money or Warrant Property becoming due on such date until
such sums or property shall be paid or delivered to such Persons or otherwise
disposed of as herein provided and will promptly notify the Trustee of its
action or failure so to act.

      Whenever the Company shall have one or more Paying Agents for any series
of Securities, it will, prior to the Payment or Settlement Date of the
Securities of that series, deposit with a Paying Agent money or Warrant Property
sufficient to pay or deliver the money or Warrant Property becoming due with
respect to such Securities on such date, such money or Warrant Property to be
held as provided by the Trust Indenture Act, and (unless such Paying Agent is
the Trustee) the Company will promptly notify the Trustee of its action or
failure so to act.

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

                                      -67-
<PAGE>
such Paying Agent will (1) comply with the provisions of the Trust Indenture Act
applicable to it as a Paying Agent and (2) during the continuance of any default
by the Company (or any other obligor upon the Securities of that series) in the
making of any payment in respect of the Securities of that series, upon the
written request of the Trustee, forthwith pay to the Trustee all money or
Warrant Property held in trust by such Paying Agent for payment in respect of
the Securities of that series.

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

      Any money or Warrant Property deposited with the Trustee or any Paying
Agent, or then held by the Company, in trust for the payment or delivery of the
amounts due on any Security of any series in accordance with its terms and
remaining unclaimed for two years after such amounts have become due and payable
or deliverable shall be paid or delivered to the Company on Company Request, or
(if then held by the Company) shall be discharged from such trust; and the
Holder of such Security shall thereafter, as an unsecured general creditor, look
only to the Company for payment or delivery thereof, and all liability of the
Trustee or such Paying Agent with respect to such trust money or property, and
all liability of the Company as trustee thereof, shall thereupon cease.

      SECTION 1004. Statement by Officers as to Default.

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

      SECTION 1005. Existence.

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

                                      -68-
<PAGE>
      SECTION 1006. Payment of Taxes and Other Claims.

      The Company will pay or discharge or cause to be paid or discharged,
before the same shall become delinquent, (1) all taxes, assessments and
governmental charges levied or imposed upon the Company or 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 1007. Payment of Additional Amounts.

      Payments under the Securities will be made without deduction or
withholding for or on account of any present or future tax, duty, assessment or
governmental charge imposed upon or as a result of such payments by Switzerland
or any jurisdiction in which a branch of the Company through which any Security
is issued is located (or any political subdivision or taxing authority thereof
or therein) (a "Relevant Jurisdiction") ("Taxes"), unless required by law. To
the extent any such Taxes are so levied or imposed, the Company will, subject to
the exceptions and limitations set forth below, pay such additional amounts
("Additional Amounts") to the Holder of any Security who is not a resident of
the Relevant Jurisdiction or any political subdivision or taxing authority
thereof or therein as may be necessary in order that every net payment of the
principal of and interest on such Security and any other amounts payable on such
Security, after withholding for or on account of such Taxes imposed upon or as a
result of such payment, will not be less than the amount provided for in such
Security to be then due and payable. However, the Company will not be required
to make any payment of Additional Amounts to any such Holder if such payment can
be made without such deduction or withholding by a paying agent other than the
one required to make such a deduction or withholding. Further, the Company will
not be required to make any payment of Additional Amounts to any such Holder for
or on account of:

      (i) any such Taxes which would not have been so imposed but for (a) the
      existence of any present or former connection between such Holder (or
      between a fiduciary, settler, beneficiary, member or shareholder of such
      Holder, if such Holder is an estate, a trust, a partnership or a
      corporation) and Switzerland (or any political subdivision or taxing
      authority thereof or therein) including, without limitation, such Holder
      (or such fiduciary, settler, beneficiary, member or shareholder) being or
      having been a citizen or resident thereof or being or having been engaged
      in a trade or business or present therein or having, or having had, a
      permanent establishment therein or (b) the presentation by or on behalf of
      the Holder of any such Security payment on a date more than 15 days after
      the date on which such

                                      -69-
<PAGE>
      payment became due and payable or the date on which payment thereof is
      duly provided for, whichever occurs later;

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

      (iii) any Taxes which are payable otherwise than by withholding from
      payments on or in respect of any Security;

      (iv) any Taxes which would not have been imposed but for the failure to
      comply with certification, information or other reporting requirements
      concerning the nationality, residence or identity of the holder or
      beneficial owner of such Security, if such compliance is required by
      statute or by regulation of or on behalf of Switzerland 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

      (v) any combination of items (i) through (iv) above;

nor shall Additional Amounts be paid with respect to any payment on a Security
to a Holder who is a fiduciary or partnership or other than the sole beneficial
owner of such payment to the extent such payment would be required 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
who would not have been entitled to the Additional Amounts had such beneficiary,
settlor, member or beneficial owner been the Holder of the Security.

      The provisions of this Section 1007 shall also apply to any Taxes imposed
by any jurisdiction in which a Person into which the Company has merged or to
which the Company has conveyed, transferred or leased its property is located.

      SECTION 1008. Waiver of Certain Covenants.

      Except as otherwise specified as contemplated by Section 301 for
Securities of such series, the Company may, with respect to the Securities of
any series, omit in any particular instance to comply with any term, provision
or condition set forth in any covenant provided pursuant to Section 301(3),
901(2) or 901(7) for the benefit of the Holders of such series or in Article
Eight or Section 1008 if before the time for such compliance, the Holders of at
least a majority in number of the Outstanding Warrants of such series shall, by
Act of such Holders, either waive such compliance in such instance or generally
waive compliance with such term, provision or condition, but no such waiver
shall extend to or affect such term, provision or condition except to the extent
so expressly waived, and, until such waiver shall become effective, the
obligations of the Company and the duties of the Trustee in respect of any such
term, provision or condition shall remain in full force and effect.

                                      -70-
<PAGE>
                                 ARTICLE ELEVEN

                            REDEMPTION OF SECURITIES

      SECTION 1101. Applicability of Article.

      Securities of any series which are redeemable before their Expiration Date
shall be redeemable in accordance with their terms and (except as otherwise
specified as contemplated by Section 301 for such Securities) in accordance with
this Article.

      SECTION 1102. Election to Redeem; Notice to Trustee.

      The election of the Company to redeem any Securities shall be evidenced by
a Board Resolution or in another manner specified as contemplated by Section 301
for such Securities. In case of any redemption at the election of the Company of
less than all the Securities of any series (including any such redemption
affecting only a single Security), the Company shall, at least 60 days prior to
the Redemption Date fixed by the Company (unless a shorter notice shall be
satisfactory to the Trustee), notify the Trustee of such Redemption Date and of
the number of Warrants of such series to be redeemed and, if applicable, the
tenor of the Warrants to be redeemed. In the case of any redemption of
Securities prior to the expiration of any restriction on such redemption
provided in the terms of such Securities or elsewhere in this Indenture, the
Company shall furnish the Trustee with an Officers' Certificate evidencing
compliance with such restriction.

      SECTION 1103. Selection by Trustee of Securities to Be Redeemed.

      If less than all the Securities of any series and of a specified tenor are
to be redeemed (unless all the Securities of such series and tenor are to be
redeemed or unless such redemption affects only a single Security), the
particular Securities to be redeemed shall be selected not more than 60 days
prior to the Redemption Date by the Trustee, from the Outstanding Securities of
such series not previously called for redemption, by such method as the Trustee
shall deem fair and appropriate, provided that the unredeemed portion of any
Security shall be in an authorized denomination (which shall not be less than
the minimum authorized denomination) for such Security. If less than all the
Securities of such series and of a specified tenor are to be redeemed (unless
such redemption affects only a single Security), the particular Securities to be
redeemed shall be selected not more than 60 days prior to the Redemption Date by
the Trustee, from the Outstanding Securities of such series and specified tenor
not previously called for redemption in accordance with the preceding sentence.

      If any Security selected for partial redemption is exercised in part
before termination of the exercise right with respect to the portion of the
Security so selected, the exercised portion of such Security shall be deemed (so
far as may be) to be the portion selected for redemption. Securities which have
been exercised during a selection

                                      -71-
<PAGE>
of Securities to be redeemed shall be treated by the Trustee as Outstanding for
the purpose of such selection.

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

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

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

      SECTION 1104. Notice of Redemption.

      Notice of redemption shall be given by first-class mail, postage prepaid,
mailed not less than 10 nor more than 60 days prior to the Redemption Date, to
each Holder of Securities to be redeemed, at his address appearing in the
Security Register.

      All notices of redemption shall state:

      (1) the Redemption Date,

      (2) the Redemption Price,

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

      (4) that on the Redemption Date the Redemption Price will become due and
      payable upon each such Security to be redeemed,

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

      (6) if applicable, the terms of exercise, the date on which the right to
      exercise the Security to be redeemed will terminate and the place or
      places where such Securities may be surrendered for exercise.

                                      -72-
<PAGE>
      Notice of redemption of Securities to be redeemed at the election of the
Company shall be given by the Company or, at the Company's request, by the
Trustee in the name and at the expense of the Company and shall be irrevocable.

      SECTION 1105. Deposit of Redemption Price.

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

      If any Security called for redemption is exercised, any money deposited
with the Trustee or with any Paying Agent or so segregated and held in trust for
the redemption of such Security shall be paid to the Company upon Company
Request or, if then held by the Company, shall be discharged from such trust.

      SECTION 1106. 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. Upon surrender of any such Security for
redemption in accordance with said notice, such Security shall be paid by the
Company at the Redemption Price.

      SECTION 1107. Securities Redeemed in Part.

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

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

                                      -73-
<PAGE>
      IN WITNESS WHEREOF, the parties hereto have caused this Indenture to be
duly executed as of the day and year first above written.

                                     UBS AG

                               By /s/ Jeff Sparks
                                  ----------------------------

                               By /s/ Louis Eber
                                  ----------------------------

                                     Trustee

                               By /s/ Stacey A. Pagliaro
                                  ----------------------------

                                      -74-

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