EXHIBIT 3.5

                                 TRUST AGREEMENT

                                       OF

                         UBS PREFERRED FUNDING TRUST IV

                  TRUST AGREEMENT, dated as of December 12, 2002, between UBS
PREFERRED FUNDING COMPANY LLC IV, a Delaware limited liability company (the
"Grantor"), and WILMINGTON TRUST COMPANY, a Delaware banking corporation (the
"Trustee"). The Grantor and the Trustee hereby agree as follows:

                  1.       The trust created hereby shall be known as "UBS
Preferred Funding Trust IV", in which name the Trustee, or the Grantor to the
extent provided herein, may cause the Trust to conduct its business, make and
execute contracts, and sue and be sued.

                  2.       It is the intention of the parties hereto that the
Trust created hereby constitute a statutory trust under Chapter 38 of Title 12
of the Delaware Code, 12 Del. Code Section 3801 et seq. (the "Statutory
Trust Act"), and that this Trust Agreement constitute the governing instrument
of the Trust. The Trustee is hereby authorized and directed to execute and file
a certificate of trust in the office of the Secretary of State of the State of
Delaware in the form attached hereto. The Trust is hereby established by the
Grantor and the Trustee for the purpose of (i) issuing noncumulative preferred
trust certificates (the "Trust Securities") representing undivided beneficial
interests in the assets of the Trust in exchange for cash and investing the
proceeds thereof in noncumulative preferred securities of the Grantor, and (ii)
engaging in such other activities as are necessary, convenient or incidental
thereto.

                  3.       Concurrent with the first issuance of any Trust
Securities by the Trust, the Grantor and the Trustee intend to enter into an
amended and restated trust agreement, satisfactory to each such party, to
provide for the contemplated operation of the Trust created hereby and the
issuance of the Trust Securities. Prior to the execution and delivery of such
amended and restated trust agreement, the Trustee shall not have any duty or
obligation hereunder or with respect to the Trust assets, except expressly as
required by this Trust Agreement or by law.

                  4.       Pursuant to Section 3806(b)(7) of the Statutory
Trust Act, the Grantor, as agent of the Trust, (a) shall prepare or cause the
preparation of and execute a Registration Statement on Form F-3 under the
Securities Act of 1933, as amended (the "Securities Act"), relating to the offer
and sale of the Trust Securities (on a delayed or continuous basis); (b) shall
prepare or cause the preparation of and execute on behalf of the Trust and file
with the Luxembourg Stock Exchange, the New York Stock Exchange or any other
stock exchange, as the case may be, a listing application and all other
applications, statements, certificates, agreements, and other instruments as
shall be necessary or desirable to cause the Trust Securities to be listed on
the Luxembourg Stock Exchange, the New York Stock Exchange or any other stock
exchange, as the case may be; (c) shall prepare, execute and file, in each case
on behalf of the Trust, such applications, reports, surety bonds, irrevocable
consents, appointments of



attorney for service of process and other papers and documents as the Grantor,
on behalf of the Trust, may deem necessary or desirable to register the Trust
Securities under, or obtain for the Trust Securities an exemption from, the
securities or "blue sky" laws of any jurisdictions; (d) shall negotiate the
terms of, and execute on behalf of the Trust, such underwriting or purchase or
placement agent agreements with one or more underwriters, managers or placement
agents relating to the offer and sale of the Trust Securities; and (e) shall
execute on behalf of the Trust any and all documents, papers and instruments as
may be desirable in connection with any of the foregoing. In the event that any
filing referred to in clauses (b) or (c) above is required by (i) the Securities
Act, (ii) the Securities and Exchange Act of 1934, as amended, (iii) the rules
and regulations of the Luxembourg Stock Exchange, the New York Stock Exchange or
any other stock exchange, as the case may be, (iv) any state securities or blue
sky laws or (v) any other applicable laws to be executed on behalf of the Trust
by the Trustee, the Trustee is hereby authorized and directed to join in any
such filing and to execute on behalf of the Trust any and all of the foregoing,
it being understood that Wilmington Trust Company, in its capacity as a Trustee
of the Trust, shall not be required to join in any such filing or execute on
behalf of the Trust any such document unless and to the extent expressly
required by the foregoing enumerated laws, rules or regulations.

                  5.       This Trust Agreement may be executed in one or more
counterparts.

                  6.       The number of Trustees initially shall be one (1) and
thereafter the number of Trustees shall be such number as shall be fixed from
time to time by a written instrument signed by the Grantor which may increase or
decrease the number of Trustees; provided, however, that the number of Trustees
shall in no event be less than one (1); and provided, further, however, that to
the extent required by the Statutory Trust Act, one Trustee shall either be a
natural person who is a resident of the State of Delaware or, if not a natural
person, an entity which has its principal place of business in the State of
Delaware and meets any other requirements imposed by applicable law. Subject to
the foregoing, the Grantor is entitled to appoint or remove without cause any
Trustee at any time. Any Trustee may resign upon 30 days prior notice to the
Grantor.

                  7.       The recitals contained in this Trust Agreement shall
be taken as statements of the Grantor, and the Trustee does not assume any
responsibility for their correctness. The Trustee makes no representations as to
the value or condition of the property of the Trust or any part thereof. The
Trustee makes no representations as to the validity or sufficiency of this Trust
Agreement or any other document pertaining to the Trust.

                  8.       (a) The Trustee and its officers, directors, agents
and employees (collectively, the "Fiduciary Indemnified Persons") shall not be
liable, responsible or accountable in damages or otherwise to the Trust, the
Grantor or any holder of the Trust Securities (the Trust, the Grantor and any
holder of the Trust Securities being a "Covered Person") for any loss, damage or
claim incurred by reason of any act or omission performed or omitted by the
Fiduciary Indemnified Persons in good faith on behalf of the Trust and in a
manner the Fiduciary Indemnified Persons reasonably believed to be within the
scope of authority conferred on the Fiduciary Indemnified Persons by this Trust
Agreement or by law, except that the Fiduciary Indemnified Persons shall be
liable for any such loss, damage or claim

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incurred by reason of the Fiduciary Indemnified Person's gross negligence or
willful misconduct with respect to such acts or omissions.

                  (b)      The Fiduciary Indemnified Persons shall be fully
protected in relying in good faith upon the records of the Trust and upon such
information, opinions, reports or statements presented to the Trust by any
person as to matters the Fiduciary Indemnified Persons reasonably believes are
within such other person's professional or expert competence and who has been
selected with reasonable care by or on behalf of the Trust, including
information, opinions, reports or statements as to the value and amount of the
assets, liabilities, profits, losses, or any other facts pertinent to the
existence and amount of assets from which distributions to holders of Trust
Securities might properly be paid.

                  (c)      No provision of this Trust Agreement shall be deemed
to require any of the Fiduciary Indemnified Persons to expend or risk funds or
otherwise incur any financial liability in the performance of any of its rights
or powers hereunder if such person shall have reasonable grounds for believing
that repayment of such funds or adequate indemnity against such risk or
liability is not reasonably assured or provided to it.

                  9.       The Grantor agrees, to the fullest extent permitted
by applicable law,

                           (a)      to indemnify and hold harmless each
         Fiduciary Indemnified Person from and against any loss, damage,
         liability, tax, penalty, expense or claim of any kind or nature
         whatsoever incurred by the Fiduciary Indemnified Persons by reason of
         the creation, operation or termination of the Trust in a manner the
         Fiduciary Indemnified Persons reasonably believed to be within the
         scope of authority conferred on the Fiduciary Indemnified Persons by
         this Trust Agreement, except that no Fiduciary Indemnified Persons
         shall be entitled to be indemnified in respect of any loss, damage or
         claim incurred by the Fiduciary Indemnified Persons by reason of gross
         negligence or willful misconduct with respect to such acts or
         omissions; and

                           (b)      to advance expenses (including legal fees)
         incurred by a Fiduciary Indemnified Person in defending any claim,
         demand, action, suit or proceeding, from time to time, prior to the
         final disposition of such claim, demand, action, suit or proceeding,
         upon receipt by the Trust of an undertaking by or on behalf of such
         Fiduciary Indemnified Persons to repay such amount if it shall be
         determined that such Fiduciary Indemnified Person is not entitled to be
         indemnified as authorized in the preceding subsection.

                  10.      The provisions of Section 9 shall survive the
termination of this Trust Agreement or the earlier resignation or removal of the
Trustee.

                  11.      The Trust may terminate without issuing any Trust
Securities at the election of the Grantor.

                  12.      This Trust Agreement and the rights of the parties
hereunder shall be governed by and interpreted in accordance with the laws of
the State of Delaware and all rights and remedies shall be governed by such laws
without regard to the principles of conflict of laws.

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

                                           UBS PREFERRED FUNDING COMPANY LLC IV,
                                           as Grantor

                                           By:  UBS AG,
                                                as Member

                                           By:  /s/ Robert Mills
                                                --------------------------------
                                                Name:   Robert Mills
                                                Title:  Chief Financial Officer
                                                        - Americas and Regional
                                                        Chief Operating Officer

                                           By:  /s/ Robert Dinerstein
                                                --------------------------------
                                                Name:   Robert Dinerstein
                                                Title:  Managing Director

                                           WILMINGTON TRUST COMPANY,
                                           as Trustee

                                           By:  /s/ Donald G. MacKelcan
                                                --------------------------------
                                                Name:   Donald G. MacKelcan
                                                Title:  Vice President

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