Document:

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                                                                    Exhibit 4.3c

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                             PAINE WEBBER GROUP INC.

                                       and

                            THE CHASE MANHATTAN BANK

                                   as Trustee

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

                          SECOND SUPPLEMENTAL INDENTURE

                           Dated as of March 14, 1997

                                     to the

                                    INDENTURE

                          Dated as of December 9, 1996

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

                      8.08% Junior Subordinated Debentures

                                    Due 2037

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                                    SECOND SUPPLEMENTAL INDENTURE, dated as of
                           March 14, 1997 (this "Second Supplemental
                           Indenture"), between PAINE WEBBER GROUP INC., a
                           corporation duly organized and existing under the
                           laws of the State of Delaware (hereinafter sometimes
                           referred to as the "Company") and THE CHASE MANHATTAN
                           BANK, a New York banking corporation, as trustee
                           (hereinafter sometimes referred to as the "Trustee")
                           under the Indenture dated as of December 9, 1996,
                           between the Company and the Trustee (the
                           "Indenture"); as set forth in Section 7.01 hereto and
                           except as otherwise set forth herein, all terms used
                           and not defined herein are used as defined in the
                           Indenture).

         WHEREAS the Company executed and delivered the Indenture to the Trustee
to provide for the future issuance of its junior subordinated debentures (the
"Debentures"), said Debentures to be issued from time to time in series as might
be determined by the Company under the Indenture, in an unlimited aggregate
principal amount which may be authenticated and delivered thereunder as in the
Indenture provided;

         WHEREAS, pursuant to the terms of the Indenture, the Company desires to
provide for the establishment of a new series of its Debentures to be known as
its 8.08% Junior Subordinated Debentures due 2037 (said series being hereinafter
referred to as the "Series 8.08% Debentures"), the form of such Series 8.08%
Debentures and the terms, provisions and conditions thereof to be as provided in
the Indenture and this Second Supplemental Indenture;

         WHEREAS the Company has caused to be formed PWG Capital Trust II (the
"Trust") as a business trust under the Business Trust Act of the State of
Delaware (12 Del. Code Sec. 801 ET SEQ.) pursuant to a declaration of trust
dated as of October 7, 1996 (the "Original Declaration"), and the filing of a
certificate of trust with the Secretary of State of the State of Delaware on
October 7, 1996;

         WHEREAS the Original Declaration is to be amended and restated in its
entirety pursuant to an Amended and Restated Declaration of Trust dated as of
March 14, 1997 (such Amended and Restated Declaration of Trust, as amended from
time to time, the "Declaration of Trust");

         WHEREAS the Trust desires to issue its 8.08% Preferred Trust Securities
(the "Preferred Securities") and sell such Preferred Securities to initial
purchasers;

         WHEREAS, in connection with such purchases of Preferred Securities and
the related purchase by the Company of the Common Securities (as defined in the
Declaration of Trust) of the Trust, the Trust will purchase as trust assets
Series 8.08% Debentures;

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                                                                               2

         WHEREAS, pursuant to the Declaration of Trust, the legal title to the
Series 8.08% Debentures shall be held by and in the name of The Chase Manhattan
Bank or its successor under the Declaration of Trust, as Property Trustee (the
"Property Trustee"), in trust for the benefit of holders of the Preferred
Securities and the Common Securities;

         WHEREAS, upon the occurrence of a Special Event (as defined in the
Declaration of Trust), the Regular Trustees (as defined in the Declaration of
Trust) of the Trust shall, unless the Series 8.08% Debentures are redeemed as
described herein, dissolve the Trust and cause to be distributed to the holders
of the Preferred Securities and Common Securities, on a pro rata basis
(determined as provided in the terms of the Preferred Securities and Common
Securities attached as Exhibits B and C to the Declaration of Trust), Series
8.08% Debentures and, in connection with a Liquidation Distribution (as defined
in the Declaration of Trust), the Regular Trustees may cause to be distributed
to holders of Preferred Securities and Common Securities, on such pro rata
basis, Series 8.08% Debentures (each a "Dissolution Event"); and

         WHEREAS the Company desires and has requested the Trustee to join with
it in the execution and delivery of this Second Supplemental Indenture, and all
requirements necessary to make this Second Supplemental Indenture a valid
instrument, enforceable in accordance with its terms, and to make the Series
8.08% Debentures, when executed by the Company and authenticated and delivered
by the Trustee, the valid obligations of the Company, have been performed and
fulfilled, and the execution and delivery of this Supplemental Indenture and the
Series 8.08% Debentures have been in all respects duly authorized.

         NOW, THEREFORE, in consideration of the purchase and acceptance of the
Series 8.08% Debentures by the holders thereof, and for the purpose of setting
forth, as provided in the Indenture, the form of the Series 8.08% Debentures and
the terms, provisions and conditions thereof, the Company covenants and agrees
with the Trustee as follows:

                                    ARTICLE I

                         GENERAL TERMS AND CONDITIONS OF
                         -------------------------------
                           THE SERIES 8.08% DEBENTURES
                           ---------------------------

         SECTION 1.01. There shall be and is hereby authorized a series of
Debentures designated the "8.08% Junior Subordinated Debentures Due 2037",
limited in aggregate principal amount to $204,896,925. The Series 8.08%
Debentures shall mature and the principal thereof shall be due and payable,
together with all accrued and unpaid interest thereon, including Compounded
Interest (as defined below) on March 1, 2037.

         SECTION 1.02. (a) Except as provided in Section 1.02(b), the Series
8.08% Debentures shall be issued in definitive registered certificated form
without interest coupons. Principal and interest on the Series 8.08% Debentures
issued in certificated form will be payable, the transfer of such Series 8.08%
Debentures will be registrable and such Series 8.08% Debentures will be
exchangeable for Series 8.08% Debentures bearing identical terms and provisions
at the office or agency of the Company in the Borough of Manhattan, The City and
State of New York; PROVIDED, HOWEVER, that payment of interest may be made at
the option of the Company by check mailed to the registered holder at such
address as shall appear in the Debenture register and that the payment of
principal with respect to the Series 8.08% Debentures will only be made upon
surrender of the Series 8.08% Debentures to the Trustee. Notwithstanding the
foregoing, so long as the Property Trustee is the record holder of Series 8.08%
Debentures, the payment of the principal of, and interest (including Compounded
Interest, if any) on, the Series 8.08% Debentures held of record by the Property
Trustee will be made by the Company in immediately available funds on the
payment date therefor to the Property Account (as defined in the Declaration of
Trust) established and maintained by the Property Trustee pursuant to the
Declaration of Trust.

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                  (b) In connection with a Dissolution Event:

                  (i) Series 8.08% Debentures in certificated form in an
         aggregate principal amount equal to the aggregate liquidation amount of
         all Preferred Securities held in book-entry form may be presented to
         the Trustee by the Property Trustee in exchange for a Global Debenture
         representing such Series 8.08% Debentures, such Global Debenture to be
         registered in the name of the Depositary, or its nominee, and delivered
         by the Trustee to the Depositary pursuant to the instructions of the
         Regular Trustees (as defined in the Declaration of Trust) for crediting
         to the accounts of the Depositary's participants. The Company, upon any
         such presentation, shall execute a Global Debenture representing the
         Series 8.08% Debentures in such aggregate principal amount and deliver
         the same to the Trustee for authentication and delivery in accordance
         with the Indenture and this Second Supplemental Indenture. Payments on
         the Series 8.08% Debentures issued as a Global Debenture will be made
         to the Depositary.

                  (ii) If any Preferred Securities are held in non book-entry
         certificated form ("Non Book-Entry Preferred Securities"), Series 8.08%
         Debentures in certificated form in an aggregate principal amount equal
         to the aggregate liquidation amount of any such Non Book-Entry
         Preferred Securities may be presented to the Trustee by the Property
         Trustee, and any Preferred Security Certificate (as defined in the
         Declaration of Trust) held in non book-entry certificated form will be
         deemed to represent beneficial interests in such Series 8.08%
         Debentures presented to the Trustee by the Property Trustee having an
         aggregate principal amount equal to the aggregate liquidation amount of
         the Non Book-Entry Preferred Securities represented by such Preferred
         Security Certificate until such Preferred Security Certificate is
         presented to the Debenture Registrar for registration of transfer or
         reissuance, at which time such Preferred Security Certificate will be
         canceled and a Series 8.08% Debenture, registered in the name of the
         holder of such Preferred Security Certificate or the transferee of the
         holder of such Preferred Security Certificate, as the case may be, with
         an aggregate principal amount equal to the aggregate liquidation amount
         of the Preferred Security Certificate canceled will be executed by the
         Company and delivered to the Trustee for authentication and delivery in
         accordance with the Indenture and this Second Supplemental Indenture.
         On issue of such Series 8.08% Debentures, Series 8.08% Debentures with
         an equivalent aggregate principal amount that were presented by the
         Property Trustee to the Trustee will be deemed to have been canceled.

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                                                                               4

                  SECTION 1.03. Each Series 8.08% Debenture will bear interest
         at the rate of 8.08% per annum from March 14, 1997 until the principal
         thereof becomes due and payable, and on any overdue principal, and (to
         the extent that payment of such interest is enforceable under
         applicable law) on any overdue installment of interest at the same rate
         per annum, compounded monthly, payable (subject to the provisions of
         Article III) monthly in arrears on the first day of each month (each,
         an "Interest Payment Date", commencing on April 1, 1997), to the Person
         in whose name such Series 8.08% Debenture (or one or more Predecessor
         Debentures) is registered at the close of business on the regular
         record date for such interest installment, which, except as set forth
         below, shall be, in respect of any Series 8.08% Debentures represented
         by a Global Debenture or of which the Property Trustee is the
         registered holder, the close of business on the Business Day next
         preceding the Interest Payment Date with respect to such interest
         installment. Notwithstanding the foregoing sentence, if the Preferred
         Securities are no longer in book-entry only form or if, pursuant to the
         provisions of Section 2.11(c) of the Indenture, the Series 8.08%
         Debentures are no longer represented solely by a Global Debenture, the
         regular record date for such interest installment shall be the close of
         business on the fifteenth day of the month immediately preceding the
         month in which the Interest Payment Date with respect to such interest
         installment occurs. Any installment of interest not punctually paid or
         duly provided for shall forthwith cease to be payable to the registered
         holder of a Series 8.08% Debenture on such regular record date and may
         be paid to the Person in whose name such Series 8.08% Debenture (or one
         or more Predecessor Debentures) is registered at the close of business
         on a special record date to be fixed by the Trustee for the payment of
         such defaulted interest, notice whereof to be given to the registered
         holders of the Series 8.08% Debentures not less than 10 days prior to
         such special record date, or may be paid at any time in any other
         lawful manner not inconsistent with the requirements of any securities
         exchange on which the Series 8.08% Debentures may be listed, and upon
         such notice as may be required by such exchange, all as more fully
         provided in the Indenture.

                  The amount of interest payable for any period will be computed
         on the basis of a 360-day year of twelve 30-day months and for any
         period shorter than a 30-day period for which interest is computed, the
         amount of interest payable will be computed on the basis of the actual
         number of days elapsed. In the event that any date on which interest is
         payable on the Series 8.08% Debentures is not a Business Day, then
         payment of interest payable on such date will be made on the next
         succeeding day which is a Business Day (and without any interest or
         other payment in respect of any such delay), except that, if such
         Business Day is in the next succeeding calendar year, such payment
         shall be made on the immediately preceding Business Day, in each case
         with the same force and effect as if made on such date.

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                                   ARTICLE II

                        OPTIONAL REDEMPTION OF THE SERIES
                        ---------------------------------
                                8.08% DEBENTURES
                                ----------------

                  SECTION 2.01. Except as provided in Section 2.02, Series 8.08%
         Debentures may not be redeemed by the Company prior to March 1, 2002.
         Subject to the terms of Article III of the Indenture, the Company shall
         have the right to redeem the Series 8.08% Debentures, in whole or in
         part, at any time or from time to time, on or after March 1, 2002, at a
         redemption price equal to 100% of the principal amount to be redeemed
         plus any accrued and unpaid interest thereon, including Compounded
         Interest, if any, to the date of such redemption (the "Optional
         Redemption Price"). Any redemption pursuant to this Section will be
         made upon not less than 30 nor more than 60 days' notice.

         SECTION 2.02. If, at any time, a Tax Event (as defined below) shall
occur or be continuing and (i) the Regular Trustees and the Company shall have
received an opinion (a "Redemption Tax Opinion") of nationally recognized
independent tax counsel experienced in such matters that, as a result of such
Tax Event, there is more than an insubstantial risk that the Company would be
precluded from deducting the interest on the Series 8.08% Debentures for United
States Federal income tax purposes even if the Series 8.08% Debentures were
distributed to the holders of Preferred Securities and Common Securities in
liquidation of such holders' interest in the Trust as set forth in the
Declaration of Trust or (ii) the Regular Trustees shall have been informed by
such tax counsel that a No Recognition Opinion (as defined below) cannot be
delivered to the Trust, the Company shall have the right, upon not less than 30
or more than 60 days notice, to redeem the Series 8.08% Debentures in whole or
in part for cash at the Optional Redemption Price within 90 days following the
occurrence of such Tax Event; PROVIDED, HOWEVER, that, if at the time there is
available to the Company or the Regular Trustees, on behalf of the Trust, the
opportunity to eliminate, within such 90-day period, such Tax Event by taking
some ministerial action ("Ministerial Action"), such as filing a form or making
an election, or pursuing some other similar reasonable measure that has no
adverse effect on the Trust, the Company or the holders of the Preferred
Securities, then the Company or the Regular Trustees, on behalf of the Trust,
will pursue such measure in lieu of redemption; and PROVIDED FURTHER that the
Company shall have no right to redeem the Series 8.08% Debentures while the
Regular Trustees, on behalf of the Trust, are pursuing any such Ministerial
Action.

         "Tax Event" means that the Regular Trustees and the Company shall have
obtained an opinion of nationally recognized independent tax counsel experienced
in such matters (a "Dissolution Tax Opinion") to the effect that on or after
March 11, 1997 as a result of (a) any amendment to, or change (including any
announced prospective change) in, the laws (or any regulations thereunder) of
the United States or any political subdivision or taxing authority thereof or
therein, (b) any amendment to, or change (including any announced prospective
change) in, an interpretation or application of any such laws or regulations by
any legislative body, court, governmental agency or regulatory authority
(including the enactment of any legislation and the publication of any judicial
decision or regulatory determination), (c) any interpretation or pronouncement
that provides for a position with respect to such laws or regulations that
differs from the theretofore generally accepted position or (d) any action taken
by any governmental agency or regulatory authority, which amendment or change is
enacted, promulgated, issued or effective or which interpretation or
pronouncement is issued or announced or which action is taken, in each case on
or after March 11, 1997, there is more than an insubstantial risk that (i) the
Trust, is, or will be within 90 days of the date thereof, subject to United
States Federal income tax with respect to income accrued or received on the
Series 8.08% Debentures, (ii) the Trust is, or will be within 90 days of the
date thereof, subject to more than a DE MINIMIS amount of other taxes, duties or
other governmental charges or (iii) interest payable by the Company to the Trust
on the Series 8.08% Debentures is not, or within 90 days of the date thereof
will not be, deductible by the Company for United States Federal income tax
purposes.

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                                                                               6

         "No Recognition Opinion" means an opinion of nationally recognized
independent tax counsel experienced in such matters, which opinion may rely on
any then applicable published revenue rulings of the Internal Revenue Service,
to the effect that the holders of the Preferred Securities will not recognize
any gain or loss for United States Federal income tax purposes as a result of a
dissolution of the Trust and distribution of the Series 8.08% Debentures as
provided in the Declaration of Trust.

         SECTION 2.03. If the Series 8.08% Debentures are only partially
redeemed pursuant to this Article II, the Series 8.08% Debentures will be
redeemed pro rata or by lot or by any other equitable method chosen by the
Trustee; PROVIDED that if, at the time of redemption, any Series 8.08%
Debentures are represented by a Global Debenture, the Depositary shall determine
the principal amount of such Series 8.08% Debentures held by each
Debentureholder to be redeemed in accordance with its customary procedures.
Notwithstanding the foregoing, if a partial redemption of the Series 8.08%
Debentures would result in the delisting of the Preferred Securities by any
national securities exchange on which the Preferred Securities are then listed,
the Company shall not be permitted to effect such partial redemption and will
only redeem the Series 8.08% Debentures in whole.

                                   ARTICLE III

                      EXTENSION OF INTEREST PAYMENT PERIOD
                      ------------------------------------

         SECTION 3.01. So long as the Company is not in default in the payment
of interest on the Series 8.08% Debentures, the Company shall have the right, at
any time during the term of the Series 8.08% Debentures, from time to time to
extend the interest payment period of the Series 8.08% Debentures for a period
not exceeding 60 consecutive monthly interest periods (an "Extended Interest
Payment Period"); PROVIDED, HOWEVER, that at the end of any such period the
Company shall pay all interest accrued and unpaid thereon (together with
interest on such accrued and unpaid interest at the rate of 8.08% per annum, to
the extent permitted by applicable law, compounded monthly ("Compounded
Interest")); and PROVIDED, FURTHER that an Extended Interest Payment Period may
not extend beyond the maturity of the Series 8.08% Debentures. During any
Extended Interest Payment Period, the Company shall not declare or pay any
dividends on, or redeem, purchase, acquire or make a distribution or liquidation
payment with respect to, any of its common stock or preferred stock or make any
payments on guarantees with respect thereto; PROVIDED, HOWEVER, that the
foregoing restrictions shall not apply to (i) dividends, redemptions, purchases,
acquisitions, distributions or payments made by the Company by way of issuance
of shares of its capital stock, (ii) payments of accrued dividends by the
Company upon the redemption, exchange or conversion of any preferred stock of
the Company as may be outstanding from time to time in accordance with the terms
of such preferred stock or (iii) cash payments made by the Company in lieu of
delivering fractional shares upon the redemption, exchange or conversion of any
preferred stock of the Company as may be outstanding from time to time in
accordance with the terms of such preferred stock. Prior to the termination of
any Extended Interest Payment Period, the Company may pay all or any portion of
the interest accrued on the Series 8.08% Debentures on any Interest Payment Date
to holders of record on the regular record date for such Interest Payment Date
or from time to time further extend such Extended Interest Payment Period;
PROVIDED that such Extended Interest Payment Period together with all such
previous and further extensions thereof may not exceed 60 consecutive monthly
interest periods. Upon the termination of any Extended Interest Payment Period
and upon the payment of all accrued and unpaid interest then due, together with
Compounded Interest, the Company may select a new Extended Interest Payment
Period. No interest shall be due and payable during an Extended Interest Payment
Period, except at the end thereof. At the end of any Extended Interest Payment
Period, the Company shall pay all interest accrued and unpaid on the Series
8.08% Debentures, including any Compounded Interest, to the holders in whose
names the Series 8.08% Debentures are registered on the Debenture Register on
the regular record date for the first Interest Payment Date occurring at or
after the end of the Extended Interest Payment Period.

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                                                                               7

         SECTION 3.02. (a) So long as the Property Trustee is the sole record
holder of the Series 8.08% Debentures, at the time the Company selects an
Extended Interest Payment Period, the Company shall give both the Property
Trustee and the Trustee written notice of its selection of such Extended
Interest Payment Period at least one Business Day prior to the earlier of (i)
the next succeeding date on which distributions on the Preferred Securities are
payable and (ii) the date on which the Trust is required to give notice of the
record or payment date for such distribution to the New York Stock Exchange (if
the Preferred Securities are then listed thereon) or other applicable
self-regulatory organization or to holders of the Preferred Securities, but in
any event not less than one Business Day prior to such record date. The Company
shall cause the Trust to give notice to the holders of the Preferred Securities
of the Company's selection of such Extended Interest Payment Period.

         (b) If as a result of a Dissolution Event, Series 8.08% Debentures have
been distributed to holders of Preferred Securities and Common Securities, at
the time the Company selects an Extended Interest Payment Period, the Company
shall give the holders of the Series 8.08% Debentures and the Trustee written
notice of its selection of such Extended Interest Payment Period at least 10
Business Days prior to the earlier of (i) the next succeeding Interest Payment
Date or (ii) the date the Company is required to give notice of the record or
payment date for such interest payment to the New York Stock Exchange (if the
Series 8.08% Debentures are then listed thereon) or other applicable
self-regulatory organization or to holders of the Series 8.08% Debentures.

         SECTION 3.03. The month in which any notice is given pursuant to
Section 3.02 shall be counted as one of the 60 consecutive monthly interest
periods permitted in the maximum Extended Interest Payment Period permitted
under this Article III.

                                   ARTICLE IV

                 COVENANTS APPLICABLE TO SERIES 8.08% DEBENTURES
                 -----------------------------------------------

         SECTION 4.01. So long as any Preferred Securities remain outstanding,
the Company will not declare or pay any dividends on, or redeem, purchase,
acquire or make a distribution or liquidation payment with respect to, any of
its common stock or preferred stock or make any payments on guarantees with
respect thereto if at such time (i) the Company shall be in default with respect
to its Guarantee Payments (as defined in the Guarantee Agreement dated as of
March 14, 1997 (the "Guarantee Agreement"), between the Company and The Chase
Manhattan Bank, as Guarantee Trustee) or other payment obligations under the
Guarantee Agreement or (ii) there shall have occurred any Event of Default under
the Indenture with respect to the Series 8.08% Debentures; PROVIDED, HOWEVER,
that the foregoing restrictions shall not apply to (i) dividends, redemptions,
purchases, acquisitions, distributions or payments made by the Company by way of
issuance of shares of its capital stock, (ii) payments of accrued dividends by
the Company upon the redemption, exchange or conversion of any preferred stock
of the Company as may be outstanding from time to time in accordance with the
terms of such preferred stock or (iii) cash payments made by the Company in lieu
of delivering fractional shares upon the redemption, exchange or conversion of
any preferred stock of the Company as may be outstanding from time to time in
accordance with the terms of such preferred stock.

         SECTION 4.02. In connection with the distribution of the Series 8.08%
Debentures to the holders of the Preferred Securities upon a Dissolution Event,
the Company will use its best efforts to list such Series 8.08% Debentures on
the New York Stock Exchange or on such other exchange as the Preferred
Securities are then listed.

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                                                                               8

         SECTION 4.03. The Company covenants and agrees for the benefit of the
holders of the Preferred Securities to comply fully with all its obligations and
agreements under the Declaration of Trust, including, without limitation, its
obligations under Article IV thereof.

         SECTION 4.04. Prior to the distribution of Series 8.08% Debentures to
the holders of Preferred Securities upon a Dissolution Event, the Company
covenants and agrees for the benefit of the holders of the Preferred Securities
(i) to remain the sole direct or indirect owner of all Common Securities issued
by the Trust and not to cause or permit the Common Securities to be transferred
except to the extent permitted by the Declaration of Trust; PROVIDED that any
permitted successor of the Company under the Indenture may succeed to the
Company's ownership of such Common Securities and (ii) to use reasonable efforts
to cause the Trust to continue to be treated as a grantor trust for United
States Federal income tax purposes, except in connection with a distribution of
the Series 8.08% Debentures as provided in the Declaration of Trust.

                                    ARTICLE V

                         FORM OF SERIES 8.08% DEBENTURES
                         -------------------------------

         SECTION 5.01. The Series 8.08% Debentures and the Trustee's Certificate
of Authentication to be endorsed thereon are to be substantially in the
following forms:

                           (FORM OF FACE OF DEBENTURE)

         [IF THE DEBENTURE IS A GLOBAL DEBENTURE, INSERT: This Debenture is a
Global Debenture within the meaning of the Indenture hereinafter referred to and
is registered in the name of a Depositary or a nominee of a Depositary. This
Debenture is exchangeable for Debentures registered in the name of a Person
other than the Depositary or its nominee only in the limited circumstances
described in the Indenture, and no transfer of this Debenture (other than a
transfer of this Debenture as a whole by the Depositary to a nominee of the
Depositary or by a nominee of the Depositary to the Depositary or another
nominee of the Depositary) may be registered except in such limited
circumstances.

         UNLESS THIS GLOBAL DEBENTURE IS PRESENTED BY AN AUTHORIZED
REPRESENTATIVE OF THE DEPOSITARY TO THE COMPANY OR ITS AGENT FOR REGISTRATION OF
TRANSFER, EXCHANGE OR PAYMENT, AND ANY DEBENTURE ISSUED IS REGISTERED IN THE
NAME OF CEDE & CO. OR IN SUCH OTHER NAME AS REQUESTED BY AN AUTHORIZED
REPRESENTATIVE OF THE DEPOSITARY AND ANY PAYMENT HEREON IS MADE TO CEDE & CO. OR
TO SUCH OTHER ENTITY AS IS REQUESTED BY AN AUTHORIZED REPRESENTATIVE OF THE
DEPOSITARY, ANY TRANSFER, PLEDGE OR OTHER USE HEREOF FOR VALUE OR OTHERWISE BY A
PERSON IS WRONGFUL SINCE THE REGISTERED OWNER HEREOF, CEDE & CO., HAS AN
INTEREST HEREIN.]

No.:                                              $

CUSIP No.: 69366F 20 8

                             PAINE WEBBER GROUP INC.

                       8.08% JUNIOR SUBORDINATED DEBENTURE
                                    DUE 2037

         Paine Webber Group Inc., a corporation duly organized and existing
under the laws of the State of Delaware (herein referred to as the "Company",
which term includes any successor corporation under the Indenture hereinafter
referred to), for value received, hereby promises to pay to , or registered
assigns, the principal sum of Dollars on March 1, 2037 and to pay interest on

<PAGE>   10
                                                                               9

said principal sum from March 14, 1997, or from the most recent interest payment
date (each such date, an "Interest Payment Date") to which interest has been
paid or duly provided for, monthly (subject to deferral as set forth herein) in
arrears on the first day of each month commencing April 1, 1997, at the rate of
8.08% per annum, until the principal hereof shall have become due and payable,
and on any overdue principal and (to the extent that payment of such interest is
enforceable under applicable law) on any overdue installment of interest at the
same rate per annum, compounded monthly. The amount of interest payable for any
period will be computed on the basis of a 360-day year of twelve 30-day months
and for any period shorter than a 30-day period for which interest is computed,
the amount of interest payable will be computed on the basis of the actual
number of days elapsed. In the event that any date on which interest is payable
on this Debenture is not a Business Day, then payment of interest payable on
such date will be made on the next succeeding day which is a Business Day (and
without any interest or other payment in respect of any such delay), except
that, if such Business Day is in the next succeeding calendar year, such payment
shall be made on the immediately preceding Business Day, in each case with the
same force and effect as if made on such date. The interest installment so
payable, and punctually paid or duly provided for, on any Interest Payment Date
will, as provided in the Indenture referred to on the reverse side hereof, be
paid to the Person in whose name this Debenture (or one or more Predecessor
Debentures) is registered at the close of business on the regular record date
for such interest installment, which shall be the close of business on the
Business Day next preceding such Interest Payment Date; PROVIDED, HOWEVER, that
if the Preferred Securities are no longer in book-entry only form or if,
pursuant to the provisions of Section 2.11(c) of the Indenture, the Series 8.08%
Debentures are no longer represented solely by a Global Debenture, the regular
record date shall be the close of business on the fifteenth day of the month
immediately preceding the month in which such Interest Payment Date occurs. Any
such interest installment not punctually paid or duly provided for shall
forthwith cease to be payable to the registered holder of this Debenture on such
regular record date, and may be paid to the Person in whose name this Debenture
(or one or more Predecessor Debentures) is registered at the close of business
on a special record date to be fixed by the Trustee for the payment of such
defaulted interest, notice whereof to be given to the registered holders of this
series of Debentures not less than 10 days prior to such special record date, or
may be paid at any time in any other lawful manner not inconsistent with the
requirements of any securities exchange on which the Series 8.08% Debentures may
be listed, and upon such notice as may be required by such exchange, all as more
fully provided in the Indenture. The principal of, and the interest on, this
Debenture shall be payable at the office or agency of the Company maintained for
that purpose in the Borough of Manhattan, The City and State of 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; PROVIDED, HOWEVER, that
payment of interest may be made at the option of the Company by check mailed to
the registered holder at such address as shall appear in the Debenture Register
and that the payment of principal will only be made upon the surrender of this
Debenture to the Trustee. Notwithstanding the foregoing, so long as the record
holder of this Debenture is the Property Trustee (as defined in the Indenture),
the payment of the principal of, and interest on, this Debenture will be made to
such account of the Property Trustee as may be designated by the Property
Trustee.

<PAGE>   11
                                                                              10

         The indebtedness evidenced by this Debenture is, to the extent provided
in the Indenture, subordinate and subject in right of payment to the prior
payment in full of all Senior Indebtedness and will rank PARI PASSU with the
Junior Subordinated Debt Securities issued by the Company and sold to PWG
Capital Trust I on December 9, 1996, and this Debenture is issued subject to the
provisions of the Indenture with respect thereto. Each holder of this Debenture,
by accepting the same, (a) agrees to and shall be bound by such provisions, (b)
authorizes and directs the Trustee on his behalf to take such action as may be
necessary or appropriate to acknowledge or effectuate the subordination so
provided and (c) appoints the Trustee his attorney-in-fact, for any and all such
purposes. Each Debentureholder, by his acceptance hereof hereby waives all
notice of the acceptance of the subordination provisions contained herein and in
the Indenture by each holder of Senior Indebtedness, whether now outstanding or
hereafter incurred, and waives reliance by each such Holder upon such
provisions.

         Unless the Certificate of Authentication hereon has been executed by
the Trustee referred to on the reverse side hereof, this Debenture shall not be
entitled to any benefit under the Indenture or be valid or obligatory for any
purpose.

         The provisions of this Debenture are continued on the reverse side
hereof and such continued provisions shall for all purposes have the same effect
as though fully set forth at this place.

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

Date:

                                        PAINE WEBBER GROUP INC.,

                                          by
                                             ----------------------------------
                                             Name:
                                             Title:

Attest:

-----------------------
       Secretary

<PAGE>   12
                                                                              11

                     (FORM OF CERTIFICATE OF AUTHENTICATION)

                          CERTIFICATE OF AUTHENTICATION

         This is one of the Debentures of the series of Debentures described in
the within-mentioned Indenture.

The Chase Manhattan Bank,                 The Chase Manhattan Bank,
  as Trustee,                               as Trustee,

                                          by
                                             ----------------------------------
                                      or     as Authentication Agent

by                                        by
   ---------------------                     ------------------------
     Authorized Officer                      Authorized Officer

                         (FORM OF REVERSE OF DEBENTURE)

         This Debenture is one of a duly authorized series of Debentures of the
Company (herein sometimes referred to as the "Debentures"), all issued or to be
issued in one or more series under and pursuant to an Indenture dated as of
December 9, 1996, duly executed and delivered between the Company and The Chase
Manhattan Bank, a New York banking corporation, as Trustee (herein referred to
as the "Trustee"), as supplemented by the Second Supplemental Indenture dated as
of March 14, 1997, between the Company and the Trustee (said Indenture as so
supplemented being hereinafter referred to as the "Indenture"), to which
Indenture and all indentures supplemental thereto reference is hereby made for a
description of the rights, limitations of rights, obligations, duties and
immunities thereunder of the Trustee, the Company and the holders of the
Debentures, and, to the extent specifically set forth in the Indenture, the
holders of Senior Indebtedness and Preferred Securities. By the terms of the
Indenture, the Debentures are issuable in series which may vary as to amount,
date of maturity, rate of interest and in other respects as in the Indenture
provided. This series of Debentures is designated the 8.08% Junior Subordinated
Debentures due 2037 (the "Series 8.08% Debentures") and is limited in aggregate
principal amount as specified in said Second Supplemental Indenture.

         Except as provided in the next paragraph, the Series 8.08% Debentures
may not be redeemed by the Company prior to March 1, 2002. The Company shall
have the right to redeem the Series 8.08% Debentures, in whole or in part, at
any time or from time to time on or after March 1, 2002 (an "Optional
Redemption"), at a redemption price equal to 100% of the principal amount to be
redeemed plus any accrued and unpaid interest, including any Compounded
Interest, thereon to the date of such redemption. Any redemption pursuant to
this paragraph will be made upon not less than 30 nor more 60 days notice. If
the Debentures are only partially redeemed by the Company pursuant to an
Optional Redemption, the Series 8.08% Debentures will be redeemed pro rata or by
lot or by any other equitable method chosen by the Trustee; PROVIDED that if, at
the time of redemption, any Series 8.08% Debentures are represented by a Global
Debenture, the Depository shall determine the principal amount of such Series
8.08% Debentures held by each holder of Series 8.08% Debentures to be redeemed
in accordance with its customary procedures.

<PAGE>   13
                                                                              12

         If, at any time, a Tax Event (as defined below) shall occur or be
continuing and (i) the Regular Trustees and the Company shall have received an
opinion (a "Redemption Tax Opinion") of nationally recognized independent tax
counsel experienced in such matters that, as a result of such Tax Event, there
is more than an insubstantial risk that the Company would be precluded from
deducting the interest on the Series 8.08% Debentures for United States Federal
income tax purposes even if the Series 8.08% Debentures were distributed to the
holders of Preferred Securities and Common Securities in liquidation of such
holders' interest in the Trust as set forth in the Declaration of Trust or (ii)
the Regular Trustees shall have been informed by such tax counsel that a No
Recognition Opinion (as defined below) cannot be delivered to the Trust, the
Company shall have the right, upon not less than 30 nor more than 60 days
notice, to redeem the Series 8.08% Debentures in whole or in part for cash at
the Optional Redemption Price within 90 days following the occurrence of such
Tax Event; PROVIDED, HOWEVER, that, if at the time there is available to the
Company or the Regular Trustees, on behalf of the Trust, the opportunity to
eliminate, within such 90-day period, the Tax Event by taking some ministerial
action ("Ministerial Action"), such as filing a form or making an election, or
pursuing some other similar reasonable measure, which has no adverse effect on
the Trust, the Company or the holders of the Preferred Securities, the Company
or the Regular Trustees, on behalf of the Trust, will pursue such measure in
lieu of redemption; and PROVIDED FURTHER that the Company shall have no right to
redeem the Series 8.08% Debentures while the Regular Trustees, on behalf of the
Trust, are pursuing any such Ministerial Action.

         "Tax Event" means that the Regular Trustees and the Company shall have
obtained an opinion of nationally recognized independent tax counsel experienced
in such matters (a "Dissolution Tax Opinion") to the effect that on or after
March 11, 1997, as a result of (a) any amendment to, or change (or announced
prospective change) in, the laws (or any regulations thereunder) of the United
States or any political subdivision or taxing authority thereof or therein, (b)
any amendment to, or change (including any announced prospective change) in, an
interpretation or application of any such laws or regulations by any legislative
body, court, governmental agency or regulatory authority (including the
enactment of any legislation and the publication of any judicial decision or
regulatory determination), (c) any interpretation or pronouncement that provides
for a position with respect to such laws or regulations that differs from the
theretofore generally accepted position or (d) any action taken by any
governmental agency or regulatory authority, which amendment or change is
enacted, promulgated, issued or effective or which interpretation or
pronouncement is issued or announced or which action is taken, in each case on
or after March 11, 1997, there is more than an insubstantial risk that (i) the
Trust is, or will be within 90 days of the date thereof, subject to United
States Federal income tax with respect to income accrued or received on the
Series 8.08% Debentures, (ii) the Trust is, or will be within 90 days of the
date thereof, subject to more than a DE MINIMIS amount of other taxes, duties or
other governmental charges or (iii) interest payable by the Company to the Trust
on the Series 8.08% Debentures is not, or within 90 days of the date thereof
will not be, deductible by the Company for United States Federal income tax
purposes.

<PAGE>   14
                                                                              13

         "No Recognition Opinion" means an opinion of nationally recognized
independent tax counsel experienced in such matters, which opinion may rely on
any then applicable published revenue rulings of the Internal Revenue Service,
to the effect that the holders of the Preferred Securities will not recognize
any gain or loss for United States Federal income tax purposes as a result of a
dissolution of the Trust and distribution of the Series 8.08% Debentures as
provided in the Declaration of Trust.

         If the Debentures are only partially redeemed by the Company pursuant
to an Optional Redemption or as a result of a Tax Event as described above, the
Debentures will be redeemed pro rata or by lot or by any other equitable method
chosen by the Trustee. Notwithstanding the foregoing, if a partial redemption of
the Series 8.08% Debentures would result in the delisting of the Preferred
Securities by any national securities exchange on which the Preferred Securities
are then listed, the Company shall not be permitted to effect such partial
redemption and will only redeem the Series 8.08% Debentures in whole.

         In the event of redemption of this Debenture in part only, a new Series
8.08% Debenture or Debentures will be issued for the unredeemed portion hereof
in the name of the holder hereof upon the cancelation of this Debenture.

         In case an Event of Default, as defined in the Indenture, shall have
occurred and be continuing, the principal of all of the Series 8.08% Debentures
may be declared, and upon such declaration shall become, due and payable, in the
manner, with the effect and subject to the conditions provided in the Indenture.

         The Indenture contains provisions for defeasance at any time of the
entire indebtedness of the Series 8.08% Debentures upon compliance by the
Company with certain conditions set forth therein.

         The Indenture contains provisions permitting the Company and the
Trustee, with the consent of the holders of not less than a majority in
aggregate principal amount of the Debentures of each series affected at the time
outstanding, as defined in Section 8.04 of the Indenture, (and, in the case of
any series of Debentures held as trust assets of a PWG Capital Trust and with
respect to which a Security Exchange has not theretofore occurred, such consent
of holders of the Preferred Securities and the Common Securities of such PWG
Capital Trust as may be required under the Declaration of Trust of such PWG
Capital Trust), to execute supplemental indentures for the purpose of adding any
provisions to or changing in any manner or eliminating any of the provisions of
the Indenture or of any supplemental indenture or of modifying in any manner the
rights of the holders of any series of Debentures; PROVIDED, HOWEVER, that no
such supplemental indenture shall (i) extend the fixed maturity of any
Debentures of any series, or reduce the principal amount thereof, or reduce the
rate or extend the time of payment of interest thereon, or reduce any premium
payable upon the redemption thereof, without the consent of the holder of each
Debenture so affected or (ii) reduce the aforesaid percentage of Debentures, the
holders of which are required to consent to any such supplemental indenture,
without the consent of the holders of each Debenture (and, in the case of any
series of Debentures held as trust assets of a PWG Capital Trust and with
respect to which a Security Exchange has not theretofore occurred, such consent
of the holders of the Preferred Securities and the Common Securities of such PWG
Capital Trust as may be required under the Declaration of Trust of such PWG
Capital Trust) then outstanding and affected thereby. The Indenture also
contains provisions permitting the Holders of a majority in aggregate principal
amount of the Debentures of a series at the time outstanding affected thereby
(subject, in the case of any series of Debentures held as trust assets of a PWG
Capital Trust and with respect to which a Security Exchange has not theretofore
occurred, to such consent of holders of Preferred Securities and Common
Securities of such PWG Capital Trust as may be required under the Declaration of
Trust of such PWG Capital Trust), on behalf of the holders of the Debentures of

<PAGE>   15
                                                                              14

such series, to waive any past default in the performance of any of the
covenants contained in the Indenture, or established pursuant to the Indenture
with respect to such series and its consequences, except a default in the
payment of the principal of, or premium, if any, or interest on, any of the
Debentures of such series. Any such consent or waiver by the registered holder
of this Debenture (unless revoked as provided in the Indenture) shall be
conclusive and binding upon such holder and upon all future holders and owners
of this Debenture and of any Debenture issued in exchange herefor or in place
hereof (whether by registration of transfer or otherwise), irrespective of
whether or not any notation of such consent or waiver is made upon this
Debenture.

         Subject to Section 13.11 of the Indenture, no reference herein to the
Indenture (other than such Section) and no provision of this Debenture or of the
Indenture shall alter or impair the obligation of the Company, which is absolute
and unconditional, to pay the principal of and premium, if any, and interest on
this Debenture at the time and place, at the rate and in the money herein
prescribed.

         So long as the Company is not in default in the payment of interest on
the Series 8.08% Debentures, the Company shall have the right, at any time
during the term of the Series 8.08% Debentures, from time to time to extend the
interest payment period of the Series 8.08% Debentures for a period not
exceeding 60 consecutive monthly interest periods (an "Extended Interest Payment
Period"); PROVIDED, HOWEVER, that at the end of any such period the Company
shall pay all interest accrued and unpaid thereon, together with any Compounded
Interest; and PROVIDED, FURTHER that an Extended Interest Payment Period may not
extend beyond the maturity of the Series 8.08% Debentures. During any Extended
Interest Payment Period, the Company shall not declare or pay any dividends on,
or redeem, purchase, acquire or make a distribution or liquidation payment with
respect to, any of its common stock or preferred stock, or make any payments on
guarantees with respect thereto; PROVIDED, HOWEVER, that the foregoing
restrictions shall not apply to (i) dividends, redemptions, purchases,
acquisitions, distributions or payments made by the Company by way of issuance
of shares of its capital stock, (ii) payments of accrued dividends by the
Company upon the redemption, exchange or conversion of any preferred stock of
the Company as may be outstanding from time to time in accordance with the terms
of such preferred stock or (iii) cash payments made by the Company in lieu of
delivering fractional shares upon the redemption, exchange or conversion of any
preferred stock of the Company as may be outstanding from time to time in
accordance with the terms of such preferred stock. Prior to the termination of
any Extended Interest Payment Period, the Company may pay all or any portion of
the interest accrued on the Series 8.08% Debentures on any Interest Payment Date
to holders of record on the regular record date for such Interest Payment Date
or from time to time further extend such Extended Interest Payment Period;
PROVIDED that such Extended Interest Payment Period together with all such
previous and further extensions thereof may not exceed 60 consecutive monthly
interest periods. Upon the termination of any Extended Interest Payment Period
and upon the payment of all accrued and unpaid interest then due, together with
Compounded Interest, the Company may select a new Extended Interest Payment
Period. No interest shall be due and payable during an Extended Interest Payment
Period, except at the end thereof. At the end of any Extended Interest Payment
Period, the Company shall pay all interest accrued and unpaid on the Series
8.08% Debentures, including any Compounded Interest which shall be payable to
the holders in whose names the Series 8.08% Debentures are registered on the
Debenture Register on the regular record date for the first Interest Payment
Date occurring on or after the end of the Extended Interest Payment Period.

<PAGE>   16
                                       15

         As provided in the Indenture and subject to certain limitations therein
set forth, this Debenture is transferable by the registered holder hereof on the
Debenture Register of the Company, upon surrender of this Debenture for
registration of transfer at the office or agency of the Company designated for
such purpose in the Borough of Manhattan, The City and State of New York,
accompanied by a written instrument or instruments of transfer in form
satisfactory to the Company or the Debenture Registrar duly executed by the
registered holder hereof or his attorney duly authorized in writing, and
thereupon one or more new Series 8.08% Debentures of authorized denominations
and for the same aggregate principal amount will be issued to the designated
transferee or transferees. No service charge will be made for any such transfer,
but the Company may require payment of a sum sufficient to cover any tax or
other governmental charge payable in relation thereto.

         Prior to due presentment for registration of transfer of this
Debenture, the Company, the Trustee, any paying agent and any Debenture
Registrar may deem and treat the registered holder hereof as the absolute owner
hereof (whether or not this Debenture shall be overdue and notwithstanding any
notice of ownership or writing hereon made by anyone other than the Debenture
Registrar) for the purpose of receiving payment of or on account of the
principal hereof and interest due hereon and for all other purposes, and neither
the Company nor the Trustee nor any paying agent nor any Debenture Registrar
shall be affected by any notice to the contrary.

         No recourse under or upon any obligation, covenant or agreement of the
Indenture, or of this Debenture, or for any claim based thereon or hereon, or
otherwise in respect thereof or hereof shall be had against any incorporator,
stockholder, officer or director, past, present or future, as such, of the
Company or of any predecessor or successor corporation, either directly or
through the Company or any such predecessor or successor corporation, whether by
virtue of any constitution, statute or rule of law, or by the enforcement of any
assessment or penalty or otherwise; it being expressly understood that this
Debenture and the obligations represented hereunder are solely corporate
obligations, and that no such personal liability whatever shall attach to, or is
or shall be incurred by, the incorporators, stockholders, officers or directors,
as such, of the Company or of any predecessor or successor corporation, or any
of them, because of the creation of this indebtedness, or under or by reason of
the obligations covenants or agreements contained in the Indenture or this
Debenture or implied therefrom; and that any and all such personal liability of
every name and nature, either at common law or in equity or by constitution or
statute, and any and all such rights and claims against every such incorporator,
stockholder, officer or director, as such, because of the creation of this
indebtedness, or under or by reason of the obligations, covenants or agreements
contained in the Indenture or in this Debenture or implied therefrom, are hereby
expressly waived and released by the acceptance hereof and as a condition of,
and as a consideration for, the execution of the Indenture and the issuance of
this Debenture.

         [IF THE DEBENTURE IS A GLOBAL DEBENTURE INSERT: This Global Debenture
is exchangeable for Debentures in definitive form under certain limited
circumstances set forth in the Indenture.]

         The Series 8.08% Debentures are issuable only in registered form
without interest coupons in denominations of $25 and any integral multiple
thereof. As provided in the Indenture and subject to certain limitations [IF THE
DEBENTURE IS A GLOBAL DEBENTURE, INSERT: herein and] therein set forth, Series
8.08% Debentures are exchangeable for a like aggregate principal amount of
Series 8.08% Debentures of a different authorized denomination, as requested by
the holder surrendering the same.

         Terms used and not defined in this Debenture shall have the meanings
assigned to them in the Indenture.

<PAGE>   17
                                                                              16

                                   ARTICLE VI

                    ORIGINAL ISSUE OF SERIES 8.08% DEBENTURES
                    -----------------------------------------

         SECTION 6.01. Series 8.08% Debentures in the aggregate principal amount
equal to $204,896,925 may, upon execution of this Second Supplemental Indenture,
be executed by the Company and delivered to the Trustee for authentication, and
the Trustee shall thereupon authenticate and make available for delivery said
Series 8.08% Debentures to or upon the written order of the Company, signed by
its Chairman of the Board, its Vice-Chairman of the Board, its President or any
Vice President and by its Treasurer or any Assistant Treasurer or its Controller
or any Assistant Controller or its Secretary or any Assistant Secretary, without
any further action by the Company.

                                   ARTICLE VII

                            MISCELLANEOUS PROVISIONS
                            ------------------------

         SECTION 7.01. Except as otherwise expressly provided in this Second
Supplemental Indenture or in the form of Series 8.08% Debenture or otherwise
clearly required by the context hereof or thereof, all terms used herein or in
said form of Series 8.08% Debenture that are defined in the Indenture shall have
the several meanings respectively assigned to them thereby.

         SECTION 7.02. The Indenture, as supplemented by this Second
Supplemental Indenture, is in all respects ratified and confirmed. This Second
Supplemental Indenture shall be deemed part of the Indenture in the manner and
to the extent herein and therein provided.

         SECTION 7.03. The recitals herein contained are made by the Company and
not by the Trustee, and the Trustee assumes no responsibility for the
correctness thereof. The Trustee makes no representation as to the validity or
sufficiency of this Second Supplemental Indenture.

         SECTION 7.04. This Second Supplemental Indenture may be executed in any
number of counterparts each of which shall be an original; but such counterparts
shall together constitute but one and the same instrument.

<PAGE>   18
                                                                              17

         IN WITNESS WHEREOF, the parties hereto have caused this Second
Supplemental Indenture to be duly executed, and their respective corporate seals
to be hereunto affixed and attested, on the date or dates indicated in the
acknowledgments and as of the day and year first above written.

                                        PAINE WEBBER GROUP INC.,

                                          by
                                             ----------------------------------
                                             Name:
                                             Title:

Attest:

Name:
Title:

                                        THE CHASE MANHATTAN BANK, as
                                        Trustee,

                                          by
                                             ----------------------------------
                                             Name:
                                             Title:

Attest:

Name:
Title:

<PAGE>   19

                               TABLE OF CONTENTS

                                                                          PAGE
                                                                          ----

                                   ARTICLE I

                         GENERAL TERMS AND CONDITIONS OF
                         -------------------------------
                           THE SERIES 8.08% DEBENTURES
                           ---------------------------

SECTION 1.01...............................................................  2
SECTION 1.02...............................................................  2
SECTION 1.03...............................................................  4

                                   ARTICLE II

                        OPTIONAL REDEMPTION OF THE SERIES
                        ---------------------------------
                                8.08% DEBENTURES
                                ----------------

SECTION 2.01...............................................................  5
SECTION 2.02...............................................................  5
SECTION 2.03...............................................................  6

                                   ARTICLE III

                      EXTENSION OF INTEREST PAYMENT PERIOD
                      ------------------------------------

SECTION 3.01................................................................ 6
SECTION 3.02...............................................................  7
SECTION 3.03...............................................................  7

                                   ARTICLE IV

                 COVENANTS APPLICABLE TO SERIES 8.08% DEBENTURES
                 -----------------------------------------------

SECTION 4.01...............................................................  7
SECTION 4.02...............................................................  7
SECTION 4.03...............................................................  8
SECTION 4.04...............................................................  8

<PAGE>   20

                                    ARTICLE V

                         FORM OF SERIES 8.08% DEBENTURES
                         -------------------------------

SECTION 5.01...............................................................  8

                                   ARTICLE VI

                    ORIGINAL ISSUE OF SERIES 8.08% DEBENTURES
                    -----------------------------------------

SECTION 6.01............................................................... 16

                                   ARTICLE VII

                            MISCELLANEOUS PROVISIONS
                            ------------------------

SECTION 7.01............................................................... 16
SECTION 7.02............................................................... 16
SECTION 7.03............................................................... 16
SECTION 7.04............................................................... 16<PAGE>   1
                                                                    Exhibit 4.3e

                                UBS AMERICAS INC.
                             (as successor by merger
                          to Paine Webber Group Inc.),

                                UBS AG, GUARANTOR

                                       AND

                        THE CHASE MANHATTAN BANK, TRUSTEE

                          FOURTH SUPPLEMENTAL INDENTURE

                         Dated: as of December 22, 2000

                           Supplemental to Indenture,
                          dated as of December 9, 1996,

                                 as amended by,
                          First Supplemental Indenture,
                          dated as of December 9, 1996,

                         Second Supplemental Indenture,
                         dated as of March 14, 1997, and

                          Third Supplemental Indenture,
                          dated as of November 3, 2000

                                   relating to
                         Junior Subordinated Debentures
<PAGE>   2
                  FOURTH SUPPLEMENTAL INDENTURE, dated as of December 22, 2000,
among UBS AMERICAS INC. (as successor by merger to Paine Webber Group Inc.), a
Delaware corporation (the "Company"), UBS AG, a Swiss banking corporation ("the
Guarantor"), and THE CHASE MANHATTAN BANK, a New York banking corporation (the
"Trustee").

                             RECITALS OF THE COMPANY

                  Pursuant to the Third Supplemental Indenture, dated as of
November 3, 2000 between Paine Webber Group Inc. ("PaineWebber") and the
Company, the Company succeeded to the obligations of PaineWebber under the
Indenture, dated as of December 9, 1996, between PaineWebber and the Trustee, as
supplemented by the First Supplemental Indenture dated as of December 9, 1996,
and the Second Supplemental Indenture dated as of March 14, 1997 (as amended by
such Supplemental Indentures, the "Junior Subordinated Indenture"), pursuant to
which PaineWebber issued its outstanding unsecured debentures, notes or other
evidences of indebtedness (the "Outstanding Junior Subordinated Notes").

                  The Company has requested the Trustee and the Guarantor to
join with it in the execution and delivery of this fourth supplemental indenture
(the "Fourth Supplemental Indenture") in order to supplement and amend the
Junior Subordinated Indenture, by amending and adding certain provisions
thereof, to permit the Company to accept the guarantee of the Guarantor of
certain of the Company's obligations.

                  The Company is a wholly owned subsidiary of the Guarantor, and
the Guarantor wishes to guarantee, on a subordinated basis, the Company's
obligations pursuant to the Junior Subordinated Indenture and the Outstanding
Junior Subordinated Notes.

                  The Company has authorized the execution and delivery of this
Fourth Supplemental Indenture by a Board Resolution, as defined in the Junior
Subordinated Indenture.

                  The Guarantor has authorized the execution and delivery of
this Fourth Supplemental Indenture by a
<PAGE>   3
resolution of or under the authority of its board of directors.

                  Section 9.01 of the Junior Subordinated Indenture provides
that a supplemental indenture may be entered into by the Company and the
Trustee, without the consent of any Holders of the Outstanding Junior
Subordinated Notes, to make any provisions with respect to matters or questions
arising under the Junior Subordinated Indenture, provided such action does not
adversely affect the interests of the Holders of Outstanding Junior Subordinated
Notes of any series in any material respect.

                  The Company has determined that the execution and delivery of
this Fourth Supplemental Indenture by the Company, the Guarantor and the Trustee
complies with said Section 9.01 and does not require the consent of any Holder
of the Outstanding Junior Subordinated Notes.

                  At the request of the Trustee, the Company has furnished the
Trustee with an Opinion of Counsel complying with the requirements of Section
9.05 of the Junior Subordinated Indenture, stating, among other things, that the
execution of this Fourth Supplemental Indenture is authorized or permitted by
the Junior Subordinated Indenture, and an Officers' Certificate and Opinion of
Counsel complying with the requirements of Section 13.06 of the Junior
Subordinated Indenture, and has delivered to the Trustee a Board Resolution as
required by Section 9.01 of the Junior Subordinated Indenture authorizing the
execution by the Company of this Fourth Supplemental Indenture and its delivery
by the Company to the Trustee.

                  All conditions and requirements necessary to make this Fourth
Supplemental Indenture a valid agreement of the Company, in accordance with the
terms of the Junior Subordinated Indenture, and a valid amendment of and
supplement to the Junior Subordinated Indenture have been done.

                  NOW THEREFORE, the Company, the Guarantor and the Trustee
hereby agree as follows:

I.  Amendments to the Junior Subordinated Indenture
<PAGE>   4
                  1.       Section 1.01 of the Junior Subordinated Indenture is
hereby amended by the insertion of the following definitions in the appropriate
alphabetical order:

                           "Guarantor" means UBS AG, a Swiss banking
         corporation, until a successor Person shall have become such pursuant
         to the applicable provisions of this Indenture and thereafter
         "Guarantor" shall mean such successor Person.

                           "Guarantor Order" means a written order signed in the
         name of the Guarantor by its Chairman of the Board, its President or a
         Vice President, and by its Treasurer, an Assistant Treasurer, its
         Controller, an Assistant Controller, its Secretary or an Assistant
         Secretary, and delivered to the Trustee.

                           "Guarantee" means the Guarantor's unconditional
         guarantee, on a subordinated basis, of the payment of the Debentures,
         as provided in Article Three-A.

                  2.       The definition of "Officer's Certificate" in Section
1.01 of the Junior Subordinated Indenture is hereby amended and restated in its
entirety as follows:

                           "Officers' Certificate" means, (i) with respect to
         the Company, a certificate signed by the Chairman of the Board, the
         Vice Chairman of the Board, the President or any Vice President, and by
         the Treasurer, the Controller, the Secretary or any Assistant
         Treasurer, Assistant Controller or Assistant Secretary, of the Company,
         and delivered to the Trustee; and (ii) with respect to the Guarantor, a
         certificate signed two persons authorized to bind the Guarantor, and
         delivered to the Trustee. Each such Officers' Certificate shall contain
         the statements provided in Section 13.06, if applicable.

                  3.       The definition of "Opinion of Counsel" in Section
1.01 of the Junior Subordinated Indenture is hereby amended and restated in its
entirety as follows:

                           "Opinion of Counsel" means a written opinion of
         counsel, who may be counsel for or an employee of

                                      -3-
<PAGE>   5
         the Company or the Guarantor and who shall be acceptable to the
         Trustee. Each Opinion of Counsel shall contain the statements provided
         in Section 13.06, if applicable.

                  4.       The Junior Subordinated Indenture is hereby amended
by the insertion of the following Article Three-A after the existing Article
Three:

                                 ARTICLE THREE-A

                                  The Guarantee

Section 3.01-A.  Unconditional Guarantee; Subordination.

                  For value received, the Guarantor hereby unconditionally and
irrevocably guarantees, as a primary obligor and not merely as a surety, for the
benefit of the Holders of the Debentures, and the obligations of the Company,
under the Indenture and the Debentures, including the due and punctual payment
of the principal of (and premium, if any) and interest on the Debentures
(including any additional interest or other amounts payable in accordance with
the terms of the Debentures) together with any other amount as may be owed from
time to time by the Company under the Indenture, when and as the same shall
become due and payable, whether at maturity, upon acceleration, redemption or
otherwise in accordance with the terms of the Debentures. UBS hereby waives
presentment, demand for payment, protest and acceptance of this guarantee and
all notices to any person (whether of nonpayment, dishonor, protest, extension
of credit to the debtor or of other matters referred to in the Indenture or
otherwise) with respect to the Debentures or the Indenture, or any other related
agreement or instrument. If the Company fails punctually to make any timely
payment under the Debentures, the Guarantor hereby agrees to cause any such
payment to be made punctually when and as the same shall become due and payable,
whether at the stated maturity or by declaration of acceleration, or otherwise,
and as if such payment were made by the Company.

                  The Guarantor hereby agrees that this guarantee is an
absolute, present and continuing guarantee of payment and not of collectability
and that its obligations hereunder

                                      -4-
<PAGE>   6
shall be unconditional, irrespective of the validity, legality or enforceability
of the Debentures or the Indenture, the absence of any action to enforce the
same or to collect from the Company, any waiver or consent by the holder of the
Debentures with respect to the provisions thereof, and the recovery of any
judgment against the Company or any action to enforce the same or any other
circumstance that might otherwise result in a legal or equitable discharge or
defense of a guarantor.

                  The Guarantor shall be subrogated to all rights of the Holders
of any Debenture against the Company in respect of any amounts paid by the
Guarantor pursuant to the provisions of the Guarantee; provided, however, that
the Guarantor shall not be entitled to enforce or to receive any payments
arising out of, or based upon, such right of subrogation until the principal of
and interest on all Securities issued hereunder shall have been paid in full.

                  This guarantee shall bind the Guarantor and its successors and
assigns. This guarantee constitutes a direct, unconditional and unsecured
obligation of the Guarantor. The obligations of the Guarantor hereunder will be
subordinated in right of payment to the prior payment in full of the deposit
liabilities of the Guarantor and all other liabilities of the Guarantor
(including all deposit liabilities and other liabilities of the head office and
all offices of the Guarantor wherever located), except (i) any liabilities which
by their terms rank pari passu with or are subordinated to the obligations of
the Guarantor under this guarantee; (ii) any liabilities which by their terms
rank pari passu with or are subordinated to liabilities which by their terms
rank pari passu with or are subordinated to the obligations of the Guarantor
under this guarantee; and (iii) any Existing Junior Subordinated Obligations.
For the avoidance of doubt, the obligations of the Guarantor hereunder will be
senior to any Existing Junior Subordinated Obligations and any liabilities which
by their terms are subordinated to the obligations of the Guarantor under this
guarantee.

                  5. Section 6.01 of the Junior Subordinated Indenture is hereby
amended by inserting the words "or the Guarantor" after the word "Company" in
subparagraph (1) thereof.

                                      -5-
<PAGE>   7
                  6. Section 6.02(b) of the Junior Subordinated Indenture is
hereby amended by inserting a comma and then the words "the Guarantor" following
the word "Company" the second and third times the word "Company" appears.

                  7. Section 6.02(c) of the Junior Subordinated Indenture is
hereby amended by (i) inserting a comma and then the words "the Guarantor" the
first and second times the word "Company" appears, in each case following the
word "Company" and (ii) inserting the words "or the Guarantor" the third time
the word "Company" appears, following the word "Company".

                  8. Section 6.08 of the Junior Subordinated Indenture is hereby
amended by inserting the words "and the Guarantor each" following the word
"Company" in each case where the word "Company" appears.

                  9. Section 7.06 of the Junior Subordinated Indenture is hereby
amended by (i) inserting the words "and the Guarantor" following the word
"Company" in the first line of subparagraph (a), (ii) replacing the word
"covenants" with the word "covenant" in the first line of subparagraph (a),
(iii) replacing the word "agrees" with the word "agree" in the first line of
subparagraph (a), and (iv) inserting the words "and the Guarantor" in
subparagraph (b) following the word "Company".

                  10.      The Junior Subordinated Indenture is hereby amended
by the insertion of the following paragraphs at the end of Article Ten:

Section 10.03. Guarantor May Consolidate, Etc., Only on Certain Terms.

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

                                      -6-
<PAGE>   8
                  (1) in case the Guarantor 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 Guarantor is merged or the Person which
         acquires by conveyance or transfer, or which leases, the properties and
         assets of the Guarantor substantially as an entirety shall be a
         corporation organized and existing under the laws of Switzerland or any
         other country, or any state or subdivision thereof or therein, and
         shall expressly assume, by an indenture supplemental hereto, executed
         and delivered to the Trustee, in form satisfactory to the Trustee, the
         performance of the Guarantee, and the performance of every covenant of
         this Indenture on the part of the Guarantor to be performed or
         observed;

                  (2) immediately after giving effect to such transaction, and
         treating any indebtedness which becomes an obligation of the Company or
         a 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; and

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

                                      -7-
<PAGE>   9
Section 10.04. Successor Substituted.

                  Upon any consolidation of the Guarantor with, or merger by the
Guarantor into, any other Person or any conveyance, transfer or lease of the
properties and assets of the Guarantor substantially as an entirety in
accordance with Section 10.03, the successor Person formed by such consolidation
or into which the Guarantor 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 Guarantor under this Indenture with the same effect as
if such successor Person had been named as the Guarantor 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 Guarantee.

                  11. Section 9.01 of the Junior Subordinated Indenture is
hereby amended by inserting the words "or the Guarantor" after the word
"Company" subparagraph (a) thereof in each case where the word "Company"
appears.

                  12. Section 4.03(c) of the Junior Subordinated Indenture is
hereby amended by (i) inserting the words "or the Guarantor" after the words
"the Company" at the beginning of clause (ii) of such subparagraph, and (ii)
inserting the words "or Guarantor Order, as the case may be" after the words
"Company Order."

                  13. Ratification and Confirmation. As amended and modified by
this Fourth Supplemental Indenture, the Junior Subordinated Indenture is in all
respects ratified and confirmed and the Junior Subordinated Indenture and this
Fourth Supplemental Indenture shall be read, taken and construed as one and the
same instrument.

                  14. Counterparts. This Fourth Supplemental Indenture may be
executed in any number of counterparts and all said counterparts executed and
delivered each as an original shall constitute but one and the same instrument.

                  15. Trustee's Duties, Responsibilities and Liabilities. The
recitals contained herein shall be taken as the statements of the Company and
the Guarantor, and the Trustee assumes no responsibility for the correctness of

                                      -8-
<PAGE>   10
same. The Trustee makes no representation as to the validity of this Fourth
Supplemental Indenture. The Trustee assumes no duties, responsibilities or
liabilities by reason of this Fourth Supplemental Indenture other than as set
forth in the Junior Subordinated Indenture, and this Fourth Supplemental
Indenture is executed and accepted by the Trustee subject to all the terms and
conditions of their acceptance of the trust under the Junior Subordinated
Indenture, as fully as if said terms and conditions were herein set forth at
length.

                                       -9-
<PAGE>   11
                  IN WITNESS WHEREOF, the parties hereto have caused this Fourth
Supplemental Indenture to be duly executed, and their respective corporate seals
to be hereunto affixed and attested, as of the day and year first above written.

                                  UBS AMERICAS INC.
                                  (as successor by merger to
                                  Paine Webber Group Inc.)

                                  By: ______________________________
                                      Name:
                                      Title:

ATTEST:

_______________________________
Name:
Title:

                                  UBS AG

                                  By: ______________________________
                                      Name:
                                      Title:

ATTEST:

_______________________________
Name:
Title:

                                  THE CHASE MANHATTAN BANK

                                  By: ______________________________
                                      Name:
                                      Title:
ATTEST:

_______________________________
Name:
Title:

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