Document:

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                                                                    Exhibit 4.21

      _____________________________________________________________________

                    PREFERRED SECURITIES GUARANTEE AGREEMENT

                       ___________________________________

                         Dated as of _________ __, _____

      _____________________________________________________________________

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<TABLE>
                                        CONTENTS
<S>                                                                                   <C>
ARTICLE I   DEFINITIONS AND INTERPRETATION ...........................................  2

  SECTION 1.1  Definitions and Interpretation ........................................  2

ARTICLE II   TRUST INDENTURE ACT .....................................................  5

  SECTION 2.1  Trust Indenture Act; Application ......................................  5

  SECTION 2.2  Lists of Holders of Securities ........................................  5

  SECTION 2.3  Reports by the Preferred Guarantee Trustee ............................  6

  SECTION 2.4  Periodic Reports to Preferred Guarantee Trustee .......................  6

  SECTION 2.5  Evidence of Compliance with Conditions Precedent ......................  6

  SECTION 2.6  Events of Default; Waiver .............................................  6

  SECTION 2.7  Event of Default; Notice ..............................................  6

  SECTION 2.8  Conflicting Interests .................................................  7

ARTICLE III POWERS, DUTIES AND RIGHTS OF PREFERRED GUARANTEE TRUSTEE .................  7

  SECTION 3.1  Powers and Duties of the Preferred Guarantee Trustee ..................  7

  SECTION 3.2  Certain Rights of Preferred Guarantee Trustee .........................  9

  SECTION 3.3  Not Responsible for Recitals or Issuance of Guarantee .................  12

ARTICLE IV PREFERRED GUARANTEE TRUSTEE ...............................................  12

  SECTION 4.1  Preferred Guarantee Trustee; Eligibility ..............................  12

  SECTION 4.2  Appointment, Removal and Resignation of Preferred Guarantee Trustees ..  13

ARTICLE V GUARANTEE ..................................................................  14

  SECTION 5.1  Guarantee .............................................................  14

  SECTION 5.2  Waiver of Notice and Demand ...........................................  14
</TABLE>

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<TABLE>
<S>                                                                       <C>
  SECTION 5.3  Obligations Not Affected ..................................  14

  SECTION 5.4  Rights of Holders .........................................  15

  SECTION 5.5  Guarantee of Payment ......................................  15

  SECTION 5.6  Subrogation ...............................................  16

  SECTION 5.7  Independent Obligations ...................................  16

ARTICLE VI LIMITATION OF TRANSACTIONS; SUBORDINATION .....................  16

  SECTION 6.1  Limitation of Transactions ................................  16

  SECTION 6.2  Ranking ...................................................  17

ARTICLE VII TERMINATION ..................................................  17

  SECTION 7.1  Termination ...............................................  17

ARTICLE VIII INDEMNIFICATION .............................................  17

  SECTION 8.1  Exculpation ...............................................  17

  SECTION 8.2  Indemnification ...........................................  18

ARTICLE IX MISCELLANEOUS .................................................  18

  SECTION 9.1  Successors and Assigns ....................................  18

  SECTION 9.2  Amendments ................................................  18

  SECTION 9.3  Notices ...................................................  19

  SECTION 9.4 Benefit ....................................................  19

  SECTION 9.5 Governing Law ..............................................  19
</TABLE>

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                    PREFERRED SECURITIES GUARANTEE AGREEMENT

     This GUARANTEE AGREEMENT (the "Preferred Securities Guarantee"), dated as
of _________ __, _____, is executed and delivered by _________________, a
____________ corporation (the "Guarantor"), and _______________, as trustee (the
"Preferred Guarantee Trustee"), for the benefit of the Holders (as defined
herein) from time to time of the Preferred Securities (as defined herein) of
________________, a Delaware statutory business trust (the "Issuer").

     WHEREAS, pursuant to an Amended and Restated Declaration of Trust (the
"Declaration"), dated as of _________ __, _____, among the trustees of the
Issuer named therein, the Guarantor, as sponsor, and the holders from time to
time of undivided beneficial interests in the assets of the Issuer, the Issuer
is issuing on the date hereof ____________ preferred securities, having an
aggregate liquidation amount of ____________ designated the ______ % Trust
Originated Preferred Securities (the "Preferred Securities");

     WHEREAS, as incentive for the Holders to purchase the Preferred Securities,
the Guarantor desires irrevocably and unconditionally to agree, to the extent
set forth in this Preferred Securities Guarantee, to pay to the Holders of the
Preferred Securities the Guarantee Payments (as defined herein) and to make
certain other payments on the terms and conditions set forth herein; and

     WHEREAS, the Guarantor is also executing and delivering a guarantee
agreement (the "Common Securities Guarantee") in substantially identical terms
to this Preferred Securities Guarantee for the benefit of the holders of the
Common Securities (as defined herein), except that if an Event of Default (as
defined in the Indenture), has occurred and is continuing, the rights of holders
of the Common Securities to receive Guarantee Payments under the Common
Securities Guarantee are subordinated to the rights of Holders of Preferred
Securities to receive Guarantee Payments under this Preferred Securities
Guarantee;

     NOW, THEREFORE, in consideration of the purchase by each Holder of
Preferred Securities, which purchase the Guarantor hereby agrees shall benefit
the Guarantor, the Guarantor executes and delivers this Preferred Securities
Guarantee for the benefit of the Holders.

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                    ARTICLE I DEFINITIONS AND INTERPRETATION

SECTION 1.1   Definitions and Interpretation

     In this Preferred Securities Guarantee, unless the context otherwise
requires:

     (a)  Capitalized terms used in this Preferred Securities Guarantee but not
          defined in the preamble above have the respective meanings assigned to
          them in this Section 1.1;

     (b)  a term defined anywhere in this Preferred Securities Guarantee has the
          same meaning throughout;

     (c)  all references to "the Preferred Securities Guarantee" or "this
          Preferred Securities Guarantee" are to this Preferred Securities
          Guarantee as modified, supplemented or amended from time to time;

     (d)  all references in this Preferred Securities Guarantee to Articles and
          Sections are to Articles and Sections of this Preferred Securities
          Guarantee, unless otherwise specified;

     (e)  a term defined in the Trust Indenture Act has the same meaning when
          used in this Preferred Securities Guarantee, unless otherwise defined
          in this Preferred Securities Guarantee or unless the context otherwise
          requires; and

     (f)  a reference to the singular includes the plural and vice versa.

     "Affiliate" has the same meaning as given to that term in Rule 405 of the
Securities Act of 1933, as amended, or any successor rule thereunder.

     "Authorized Officer" of a Person means any Person that is authorized to
bind such Person.

     "Business Day" means any day other than a day on which banking institutions
in the City of New York, New York or Chicago Illinois are authorized or required
by any applicable law to close.

     "Common Securities" means the securities representing common undivided
beneficial interests in the assets of the Issuer.

     "Corporate Trust Office" means the office of the Preferred Guarantee
Trustee at which the corporate trust business of the Preferred Guarantee Trustee
shall, at any

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particular time, be principally administered, which office at the date of
execution of this Agreement is located at ___________________________________.

     Covered Person" means any Holder or beneficial owner of Preferred
Securities.

     "Debentures" means the series of junior subordinated debt securities of the
Guarantor designated the ____% Subordinated Deferrable Interest Notes due
______, _____ held by the Property Trustee (as defined in the Declaration) of
the Issuer.

     "Event of Default" means a default by the Guarantor on any of its payment
or other obligations under this Preferred Securities Guarantee.

     "Guarantee Payments" means the following payments or distributions, without
duplication, with respect to the Preferred Securities, to the extent not paid or
made by the Issuer: (i) any accrued and unpaid Distributions (as defined in the
Declaration) that are required to be paid on such Preferred Securities to the
extent the Issuer shall have funds available therefor, (ii) the redemption
price, including all accrued and unpaid Distributions to the date of redemption
(the "Redemption Price") to the extent the Issuer has funds available therefor,
with respect to any Preferred Securities called for redemption by the Issuer,
and (iii) upon a voluntary or involuntary dissolution, winding-up or termination
of the Issuer (other than in connection with the distribution of Debentures to
the Holders in exchange for Preferred Securities as provided in the
Declaration), the lesser of (a) the aggregate of the liquidation amount and all
accrued and unpaid Distributions on the Preferred Securities to the date of
payment, to the extent the Issuer shall have funds available therefor, and (b)
the amount of assets of the Issuer remaining available for distribution to
Holders in liquidation of the Issuer (in either case, the "Liquidation
Distribution"). If an event of default under the Indenture has occurred and is
continuing, the rights of holders of the Common Securities to receive payments
under the Common Securities Guarantee Agreement are subordinated to the rights
of Holders of Preferred Securities to receive Guarantee Payments.

     "Holder" shall mean any holder, as registered on the books and records of
the Issuer of any Preferred Securities; provided, however, that, in determining
whether the holders of the requisite percentage of Preferred Securities have
given any request, notice, consent or waiver hereunder, "Holder" shall not
include the Guarantor or any Affiliate of the Guarantor.

     "Indemnified Person" means the Preferred Guarantee Trustee, any Affiliate
of the Preferred Guarantee Trustee, or any officers, directors, shareholders,
members,

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partners, employees, representatives, nominees, custodians or agents of the
Preferred Guarantee Trustee.

     "Indenture" means the Indenture dated as of _________ __, _____, between
the Guarantor (the "Debenture Issuer") and ____________________, as trustee, and
any indenture supplemental thereto pursuant to which certain subordinated debt
securities of the Debenture Issuer are to be issued to the Property Trustee of
the Issuer.

     "Majority in liquidation amount of the Securities" means, except as
provided by the Trust Indenture Act, a vote by Holder(s) of Preferred
Securities, voting separately as a class, of more than 50% of the liquidation
amount (including the stated amount that would be paid on redemption,
liquidation or otherwise, plus accrued and unpaid Distributions to the date upon
which the voting percentages are determined) of all Preferred Securities.

     "Officers' Certificate" means, with respect to any Person, a certificate
signed by two Authorized Officers of such Person. Any Officers' Certificate
delivered with respect to compliance with a condition or covenant provided for
in this Preferred Securities Guarantee shall include:

     (a)  a statement that each officer signing the Officers' Certificate has
          read the covenant or condition and the definition relating thereto;

     (b)  a brief statement of the nature and scope of the examination or
          investigation undertaken by each officer in rendering the Officers'
          Certificate;

     (c)  a statement that each such officer has made such examination or
          investigation as, in such officer's opinion, is necessary to enable
          such officer to express an informed opinion as to whether or not such
          covenant or condition has been complied with; and

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

     "Person" means a legal person, including any individual, corporation,
estate, partnership, joint venture, association, joint stock company, limited
liability company, trust, unincorporated association, or government or any
agency or political subdivision thereof, or any other entity of whatever nature.

     "Preferred Guarantee Trustee" means ____________________, until a Successor
Preferred Guarantee Trustee has been appointed and has accepted such

                                      -4-

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appointment pursuant to the terms of this Preferred Securities Guarantee and
thereafter means each such Successor Preferred Guarantee Trustee.

     "Responsible Officer" means, with respect to the Preferred Guarantee
Trustee, any officer assigned to administer corporate trust matters and also
means, with respect to a particular matter, any other officer to whom such
matter is referred because of that officer's knowledge of and familiarity with
the particular subject.

     "Successor Preferred Guarantee Trustee" means a successor Preferred
Guarantee Trustee possessing the qualifications to act as Preferred Guarantee
Trustee under Section 4.1.

     "Trust Indenture Act" means the Trust Indenture Act of 1939, as amended.

                         ARTICLE II TRUST INDENTURE ACT

SECTION 2.1   Trust Indenture Act; Application

     (a)  This Preferred Securities Guarantee is subject to the provisions of
the Trust Indenture Act that are required to be part of this Preferred
Securities Guarantee and shall, to the extent applicable, be governed by such
provisions; and

     (b)  if and to the extent that any provision of this Preferred Securities
Guarantee limits, qualifies or conflicts with the duties imposed by Sections 310
to 317, inclusive, of the Trust Indenture Act, such imposed duties shall
control.

SECTION 2.2   Lists of Holders of Securities

     (a)  The Guarantor shall provide the Preferred Guarantee Trustee with a
list, in such form as the Preferred Guarantee Trustee may reasonably require, of
the names and addresses of the Holders of the Preferred Securities ("List of
Holders") as of such date, (i) within 14 days after January 1 and June 30 of
each year, and (ii) at any other time within 30 days of receipt by the Guarantor
of a written request for a List of Holders as of a date no more than 14 days
before such List of Holders is given to the Preferred Guarantee Trustee
provided, that the Guarantor shall not be obligated to provide such List of
Holders at any time the List of Holders does not differ from the most recent
List of Holders given to the Preferred Guarantee Trustee by the Guarantor. The
Preferred Guarantee Trustee may destroy any List of Holders previously given to
it on receipt of a new List of Holders.

     (b)  The Preferred Guarantee Trustee shall comply with its obligations
under 311(a), 311(b) and 312(b) of the Trust Indenture Act.

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SECTION 2.3   Reports by the Preferred Guarantee Trustee

     Within 60 days after May 15 of each year, the Preferred Guarantee Trustee
shall provide to the Holders of the Preferred Securities such reports as are
required by Section 313 of the Trust Indenture Act, if any, in the form and in
the manner provided by Section 313 of the Trust Indenture Act.

SECTION 2.4   Reports to Preferred Guarantee Trustee

     The Guarantor shall provide to the Preferred Guarantee Trustee such
documents, reports and information as required by Section 314 (if any) and the
compliance certificate required by Section 314 of the Trust Indenture Act in the
form, in the manner and at the times required by Section 314 of the Trust
Indenture Act.

SECTION 2.5   Evidence of Compliance with Conditions Precedent

     The Guarantor shall provide to the Preferred Guarantee Trustee such
evidence of compliance with any conditions precedent, if any, provided for in
this Preferred Securities Guarantee that relate to any of the matters set forth
in Section 314(c) of the Trust Indenture Act. Any certificate or opinion
required to be given by an officer pursuant to Section 314(c)(1) may be given in
the form of an Officers' Certificate.

SECTION 2.6   Events of Default; Waiver

     The Holders of a Majority in liquidation amount of Preferred Securities
may, by vote, on behalf of the Holders of all of the Preferred Securities, waive
any past Event of Default and its consequences. Upon such waiver, any such Event
of Default shall cease to exist, and any Event of Default arising therefrom
shall be deemed to have been cured, for every purpose of this Preferred
Securities Guarantee, but no such waiver shall extend to any subsequent or other
default or Event of Default or impair any right consequent thereon.

SECTION 2.7   Event of Default; Notice

     (a)  The Preferred Guarantee Trustee shall, within 90 days after the
occurrence of an Event of Default actually known to a Responsible Officer of the
Preferred Guarantee Truistee, transmit by mail, first class postage prepaid, to
the Holders of the Preferred Securities, notices of all such Events of Default,
unless such defaults have been cured before the giving of such notice, provided,
that, the Preferred Guarantee Trustee shall be protected in withholding such
notice, to the extent permitted by the Trust Indenture Act, if and so long as a
Responsible Officer of the

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Preferred Guarantee Trustee in good faith determines that the withholding of
such notice is in the interests of the Holders of the Preferred Securities.

     (b)  The Preferred Guarantee Trustee shall not be deemed to have knowledge
of any Event of Default unless the Preferred Guarantee Trustee shall have
received written notice, or a Responsible Officer of the Preferred Guarantee
Trustee charged with the administration of the Declaration shall have obtained
actual knowledge thereof.

SECTION 2.8   Conflicting Interests

     The Declaration shall be deemed to be specifically described in this
Preferred Securities Guarantee for the purposes of clause (i) of the first
proviso contained in Section 310(b) of the Trust Indenture Act.

               ARTICLE III POWERS, DUTIES AND RIGHTS OF PREFERRED
                               GUARANTEE TRUSTEE

SECTION 3.1   Powers and Duties of the Preferred Guarantee Trustee

     (a)  This Preferred Securities Guarantee shall be held by the Preferred
Guarantee Trustee for the benefit of the Holders of the Preferred Securities,
and the Preferred Guarantee Trustee shall not transfer this Preferred Securities
Guarantee to any Person except a Holder of Preferred Securities exercising his
or her rights pursuant to Section 5.4(b) or to a Successor Preferred Guarantee
Trustee on acceptance by such Successor Preferred Guarantee Trustee of its
appointment to act as Successor Preferred Guarantee Trustee. The right, title
and interest of the Preferred Guarantee Trustee shall automatically vest in any
Successor Preferred Guarantee Trustee, and such vesting and cessation of title
shall be effective whether or not conveyancing documents have been executed and
delivered pursuant to the appointment of such Successor Preferred Guarantee
Trustee.

     (b)  If an Event of Default actually known to a Responsible Officer of the
Preferred Guarantee Trustee has occurred and is continuing, the Preferred
Guarantee Trustee shall enforce this Preferred Securities Guarantee for the
benefit of the Holders of the Preferred Securities.

     (c)  The Preferred Guarantee Trustee, before the occurrence of any Event of
Default and after the curing of all Events of Default that may have occurred,
shall undertake to perform only such duties as are specifically set forth in
this Preferred Securities Guarantee, and no implied covenants shall be read into
this Preferred Securities Guarantee against the Preferred Guarantee Trustee. In
case an Event of

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<PAGE>

Default has occurred (that has not been cured or waived pursuant to Section 2.6)
and is actually known to a Responsible Officer of the Preferred Guarantee
Trustee, the Preferred Guarantee Trustee shall exercise such of the rights and
powers vested in it by this Preferred Securities Guarantee, and use the same
degree of care and skill in its exercise thereof, as a prudent person would
exercise or use under the circumstances in the conduct of his or her own
affairs.

     (d)  No provision of this Preferred Securities Guarantee shall be construed
to relieve the Preferred Guarantee Trustee from liability for its own negligent
action, its own negligent failure to act, or its own willful misconduct, except
that:

     (i)  prior to the occurrence of any Event of Default and after the curing
          or waiving of all such Events of Default that may have occurred:

          (A)  the duties and obligations of the Preferred Guarantee Trustee
               shall be determined solely by the express provisions of this
               Preferred Securities Guarantee, and the Preferred Guarantee
               Trustee shall not be liable except for the performance of such
               duties and obligations as are specifically set forth in this
               Preferred Securities Guarantee, and no implied covenants or
               obligations shall be read into this Preferred Securities
               Guarantee against the Preferred Guarantee Trustee; and

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

     (ii) the Preferred Guarantee Trustee shall not be liable for any error of
          judgment made in good faith by a Responsible Officer of the Preferred
          Guarantee Trustee, unless it shall be proved that the Preferred
          Guarantee Trustee was negligent in ascertaining the pertinent facts
          upon which such judgment was made;

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<PAGE>

     (iii) the Preferred Guarantee Trustee shall not be liable with respect to
           any action taken or omitted to be taken by it in good faith in
           accordance with the direction of the Holders of not less than a
           Majority in liquidation amount of the Preferred Securities relating
           to the time, method and place of conducting any proceeding for any
           remedy available to the Preferred Guarantee Trustee, or exercising
           any trust or power conferred upon the Preferred Guarantee Trustee
           under this Preferred Securities Guarantee; and

     (iv)  no provision of this Preferred Securities Guarantee shall require the
           Preferred Guarantee Trustee to expend or risk its own funds or
           otherwise incur personal financial liability in the performance of
           any of its duties or in the exercise of any of its rights or powers,
           if the Preferred Guarantee Trustee shall have reasonable grounds for
           believing that the repayment of such funds or liability is not
           reasonably assured to it under the terms of this Preferred Securities
           Guarantee or indemnity, reasonably satisfactory to the Preferred
           Guarantee Trustee, against such risk or liability is not reasonably
           assured to it.

SECTION 3.2   Certain Rights of Preferred Guarantee Trustee

     (a)   Subject to the provisions of Section 3.1:

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

           (ii)  Any direction or act of the Guarantor contemplated by this
                 Preferred Securities Guarantee shall be sufficiently evidenced
                 by an Officers' Certificate.

           (iii) Whenever, in the administration of this Preferred Securities
                 Guarantee, the Preferred Guarantee Trustee shall deem it
                 desirable that a matter be proved or established before taking,
                 suffering or omitting any action hereunder, the Preferred
                 Guarantee Trustee (unless other evidence is herein specifically
                 prescribed) may, in the absence of bad faith on its part,
                 request and conclusively rely upon an Officers' Certificate
                 which, upon

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<PAGE>

                 receipt of such request, shall be promptly delivered by the
                 Guarantor.

          (iv)   The Preferred Guarantee Trustee shall have no duty to see to
                 any recording, filing or registration of any instrument (or any
                 rerecording, refiling or registration thereof).

          (v)    The Preferred Guarantee Trustee may consult with counsel of its
                 choice, and the written advice or opinion of such counsel with
                 respect to legal matters shall be full and complete
                 authorization and protection in respect of any action taken,
                 suffered or omitted by it hereunder in good faith and in
                 accordance with such advice or opinion. Such counsel may be
                 counsel to the Guarantor or any of its Affiliates and may
                 include any of its employees. The Preferred Guarantee Trustee
                 shall have the right at any time to seek instructions
                 concerning the administration of this Preferred Securities
                 Guarantee from any court of competent jurisdiction.

          (vi)   The Preferred Guarantee Trustee shall be under no obligation to
                 exercise any of the rights or powers vested in it by this
                 Preferred Securities Guarantee at the request or direction of
                 any Holder, unless such Holder shall have provided to the
                 Preferred Guarantee Trustee such security and indemnity,
                 reasonably satisfactory to the Preferred Guarantee Trustee,
                 against the costs, expenses (including attorneys' fees and
                 expenses and the expenses of the Preferred Guarantee Trustee's
                 agents, nominees or custodians) and liabilities that might be
                 incurred by it in complying with such request or direction,
                 including such reasonable advances as may be requested by the
                 Preferred Guarantee Trustee; provided that, nothing contained
                 in this Section 3.2(a)(vi) shall be taken to relieve the
                 Preferred Guarantee Trustee, upon the occurrence of an Event of
                 Default, of its obligation to exercise the rights and powers
                 vested in it by this Preferred Securities Guarantee.

          (vii)  The Preferred Guarantee Trustee shall not be bound to make any
                 investigation into the facts or matters stated in any
                 resolution, certificate, statement, instrument, opinion,
                 report, notice, request, direction, consent, order, bond,
                 debenture, note, other evidence of indebtedness or other paper
                 or document, but the Preferred Guarantee Trustee, in its
                 discretion, may make such further

                                      -10-

<PAGE>

                 inquiry or investigation into such facts or matters as it may
                 see fit.

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

          (ix)   Any action taken by the Preferred Guarantee Trustee or its
                 agents hereunder shall bind the Holders of the Preferred
                 Securities, and the signature of the Preferred Guarantee
                 Trustee or its agents alone shall be sufficient and effective
                 to perform any such action. No third party shall be required to
                 inquire as to the authority of the Preferred Guarantee Trustee
                 to so act or as to its compliance with any of the terms and
                 provisions of this Preferred Securities Guarantee, both of
                 which shall be conclusively evidenced by the Preferred
                 Guarantee Trustee's or its agent's taking such action.

          (x)    Whenever in the administration of this Preferred Securities
                 Guarantee the Preferred Guarantee Trustee shall deem it
                 desirable to receive instructions with respect to enforcing any
                 remedy or right or taking any other action hereunder, the
                 Preferred Guarantee Trustee (i) may request instructions from
                 the Holders of a Majority in liquidation amount of the
                 Preferred Securities, (ii) may refrain from enforcing such
                 remedy or right or taking such other action until such
                 instructions are received, and (iii) shall be protected in
                 conclusively relying on or acting in accordance with such
                 instructions.

     (b)  No provision of this Preferred Securities Guarantee shall be deemed to
impose any duty or obligation on the Preferred Guarantee Trustee to perform any
act or acts or exercise any right, power, duty or obligation conferred or
imposed on it in any jurisdiction in which it shall be illegal, or in which the
Preferred Guarantee Trustee shall be unqualified or incompetent in accordance
with applicable law, to perform any such act or acts or to exercise any such
right, power, duty or obligation. No permissive power or authority available to
the Preferred Guarantee Trustee shall be construed to be a duty.

                                      -11-

<PAGE>

SECTION 3.3   Not Responsible for Recitals or Issuance of Guarantee

     The recitals contained in this Guarantee shall be taken as the statements
of the Guarantor, and the Preferred Guarantee Trustee does not assume any
responsibility for their correctness. The Preferred Guarantee Trustee makes no
representation as to the validity or sufficiency of this Preferred Securities
Guarantee.

                     ARTICLE IV PREFERRED GUARANTEE TRUSTEE

SECTION 4.1   Preferred Guarantee Trustee; Eligibility

     (a)  There shall at all times be a Preferred Guarantee Trustee which shall:

          (i)  not be an Affiliate of the Guarantor; and

          (ii) be a bank organized and doing business under the laws of the
               United States of America or any State or Territory thereof or of
               the District of Columbia, or a bank or Person permitted by the
               Securities and Exchange Commission to act as an institutional
               trustee under the Trust Indenture Act, authorized under such laws
               to exercise corporate trust powers, having a combined capital and
               surplus of at least 50 million U.S. dollars ($50,000,000), and
               subject to supervision or examination by Federal, State,
               Territorial or District of Columbia authority. If such
               corporation publishes reports of condition at least annually,
               pursuant to law or to the requirements of the supervising or
               examining authority referred to above, then, for the purposes of
               this Section 4.1(a)(ii), the combined capital and surplus of such
               corporation shall be deemed to be its combined capital and
               surplus as set forth in its most recent report of condition so
               published.

     (b)  If at any time the Preferred Guarantee Trustee shall cease to be
eligible to so act under Section 4.1(a), the Preferred Guarantee Trustee shall
immediately resign in the manner and with the effect set out in Section 4.2(c).

     (c)  If the Preferred Guarantee Trustee has or shall acquire any
"conflicting interest" within the meaning of Section 310(b) of the Trust
Indenture Act, the Preferred Guarantee Trustee and Guarantor shall in all
respects comply with the provisions of Section 310(b) of the Trust Indenture
Act.

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SECTION 4.2   Appointment, Removal and Resignation of Preferred Guarantee
              Trustees

     (a)  Subject to Section 4.2(b), the Preferred Guarantee Trustee may be
appointed or removed without cause at any time by the Guarantor.

     (b)  The Preferred Guarantee Trustee shall not be removed in accordance
with Section 4.2(a) until a Successor Preferred Guarantee Trustee has been
appointed and has accepted such appointment by written instrument executed by
such Successor Preferred Guarantee Trustee and delivered to the Guarantor.

     (c)  The Preferred Guarantee Trustee appointed to office shall hold office
until a Successor Preferred Guarantee Trustee shall have been appointed or until
its removal or resignation. The Preferred Guarantee Trustee may resign from
office (without need for prior or subsequent accounting) by an instrument in
writing executed by the Preferred Guarantee Trustee and delivered to the
Guarantor, which resignation shall not take effect until a Successor Preferred
Guarantee Trustee has been appointed and has accepted such appointment by
instrument in writing executed by such Successor Preferred Guarantee Trustee and
delivered to the Guarantor and the resigning Preferred Guarantee Trustee.

     (d)  If no Successor Preferred Guarantee Trustee shall have been appointed
and accepted appointment as provided in this Section 4.2 within 60 days after
delivery to the Guarantor of an instrument of resignation, the resigning
Preferred Guarantee Trustee may petition any court of competent jurisdiction for
appointment of a Successor Preferred Guarantee Trustee. Such court may
thereupon, after prescribing such notice, if any, as it may deem proper, appoint
a Successor Preferred Guarantee Trustee.

     (e)  No Preferred Guarantee Trustee shall be liable for the acts or
omissions to act of any Successor Preferred Guarantee Trustee.

     (f)  Upon termination of this Preferred Securities Guarantee or removal or
resignation of the Preferred Guarantee Trustee pursuant to this Section 4.2, the
Guarantor shall pay to the Preferred Guarantee Trustee all amounts accrued to
the date of such termination, removal or resignation.

                                      -13-

<PAGE>

                               ARTICLE V GUARANTEE

SECTION 5.1   Guarantee

     The Guarantor irrevocably and unconditionally agrees to pay in full to the
Holders the Guarantee Payments (without duplication of amounts theretofore paid
by the Issuer), as and when due, regardless of any defense, right of set-off or
counterclaim that the Issuer may have or assert. The Guarantor's obligation to
make a Guarantee Payment may be satisfied by direct payment of the required
amounts by the Guarantor to the Holders or by causing the Issuer to pay such
amounts to the Holders. Notwithstanding anything to the contrary herein, the
Guarantor retains all of its rights under the Indenture to extend the interest
payment period on the Debentures and the Guarantor shall not be obligated
hereunder to pay during an Extension Period (as defined in the Indenture) any
monthly distributions on the Preferred Securities.

SECTION 5.2   Waiver of Notice and Demand

     The Guarantor hereby waives notice of acceptance of this Preferred
Securities Guarantee and of any liability to which it applies or may apply,
presentment, demand for payment, any right to require a proceeding first against
the Issuer or any other Person before proceeding against the Guarantor, protest,
notice of nonpayment, notice of dishonor, notice of redemption and all other
notices and demands.

SECTION 5.3   Obligations Not Affected

     Except as otherwise provided herein, the obligations, covenants, agreements
and duties of the Guarantor under this Preferred Securities Guarantee shall in
no way be affected or impaired by reason of the happening from time to time of
any of the following:

     (a)  the release or waiver, by operation of law or otherwise, of the
performance or observance by the Issuer of any express or implied agreement,
covenant, term or condition relating to the Preferred Securities to be performed
or observed by the Issuer;

     (b)  the extension of time for the payment by the Issuer of all or any
portion of the Distributions, Redemption Price, Liquidation Distribution or any
other sums payable under the terms of the Preferred Securities or the extension
of time for the performance of any other obligation under, arising out of, or in
connection with, the Preferred Securities (other than an extension of time for
payment of Distributions, Redemption Price, Liquidation Distribution or other
sum payable that results from the

                                      -14-

<PAGE>

extension of any interest payment period on the Debentures or any extension of
the maturity date of the Debentures permitted by the Indenture);

     (c)  any failure, omission, delay or lack of diligence on the part of the
Holders to enforce, assert or exercise any right, privilege, power or remedy
conferred on the Holders pursuant to the terms of the Preferred Securities, or
any action on the part of the Issuer granting indulgence or extension of any
kind;

     (d)  the voluntary or involuntary liquidation, dissolution, sale of any
collateral, receivership, insolvency, bankruptcy, assignment for the benefit of
creditors, reorganization, arrangement, composition or readjustment of debt of,
or other similar proceedings affecting, the Issuer or any of the assets of the
Issuer;

     (e)  any invalidity of, or defect or deficiency in, the Preferred
Securities;

     (f)  the settlement or compromise of any obligation guaranteed hereby or
hereby incurred; or

     (g)  any other circumstance whatsoever that might otherwise constitute a
legal or equitable discharge or defense of a guarantor, it being the intent of
this Section 5.3 that the obligations of the Guarantor hereunder shall be
absolute and unconditional under any and all circumstances.

     There shall be no obligation of the Holders to give notice to, or obtain
consent of, the Guarantor with respect to the happening of any of the foregoing.

SECTION 5.4   Rights of Holders

     (a)  The Holders of a Majority in liquidation amount of the Preferred
Securities have the right to direct the time, method and place of conducting of
any proceeding for any remedy available to the Preferred Guarantee Trustee in
respect of this Preferred Securities Guarantee or exercising any trust or power
conferred upon the Preferred Guarantee Trustee under this Preferred Securities
Guarantee.

     (b)  Any Holder of Preferred Securities may institute a legal proceeding
directly against the Guarantor to enforce its rights under this Preferred
Securities Guarantee, without first instituting a legal proceeding against the
Issuer, the Preferred Guarantee Trustee or any other Person.

SECTION 5.5   Guarantee of Payment

     This Preferred Securities Guarantee creates a guarantee of payment and not
of collection.

                                      -15-

<PAGE>

SECTION 5.6   Subrogation

     The Guarantor shall be subrogated to all (if any) rights of the Holders of
Preferred Securities against the Issuer in respect of any amounts paid to such
Holders by the Guarantor under this Preferred Securities Guarantee; provided,
however, that the Guarantor shall not (except to the extent required by
mandatory provisions of law) be entitled to enforce or exercise any right that
it may acquire by way of subrogation or any indemnity, reimbursement or other
agreement, in all cases as a result of payment under this Preferred Securities
Guarantee, if, at the time of any such payment, any amounts are due and unpaid
under this Preferred Securities Guarantee. If any amount shall be paid to the
Guarantor in violation of the preceding sentence, the Guarantor agrees to hold
such amount in trust for the Holders and to pay over such amount to the Holders.

SECTION 5.7   Independent Obligations

     The Guarantor acknowledges that its obligations hereunder are independent
of the obligations of the Issuer with respect to the Preferred Securities, and
that the Guarantor shall be liable as principal and as debtor hereunder to make
Guarantee Payments pursuant to the terms of this Preferred Securities Guarantee
notwithstanding the occurrence of any event referred to in subsections (a)
through (g), inclusive, of Section 5.3 hereof.

              ARTICLE VI LIMITATION OF TRANSACTIONS; SUBORDINATION

SECTION 6.1   Limitation of Transactions

     So long as any Preferred Securities remain outstanding, if there shall have
occurred an Event of Default or an event of default under the Declaration, then
(a) the Guarantor shall not declare or pay any dividend on, make any
distributions with respect to, or redeem, purchase, acquire or make a
liquidation payment with respect to, any of its capital stock, (b) the Guarantor
shall not make any payment of interest, principal or premium, if any, on or
repay, repurchase or redeem any debt securities (including guarantees) issued by
the Guarantor which rank pari passu with or junior to the Debentures or (c) the
Guarantor shall not make any guarantee payments with respect to the foregoing
(other than, with respect to clauses (a), (b) and (c), (i) dividends or
distributions in shares of, or options, warrants or rights to subscribe for or
purchase shares of, common stock of the Guarantor; (ii) any declaration of a
dividend in connection with the implementation of a shareholder's rights plan,
or the issuance of stock under any such plan in the future, or the redemption or
repurchase of any such rights pursuant thereto; (iii) payments under the
Preferred Securities Guarantee Agreement; (iv) as a direct result of, and only
to the extent required in

                                      -16-

<PAGE>

order to avoid the issuance of fractional shares of capital stock, following a
reclassification of the Guarantor's capital stock or the exchange or conversion
of one class or series of the Guarantor's capital stock for another class or
series of the Guarantor's capital stock; and (v) the purchase of fractional
interests in shares of the Guarantor's capital stock pursuant to the conversion
or exchange provisions of such capital stock or the security being converted or
exchanged).

SECTION 6.2   Ranking

     This Preferred Securities Guarantee will constitute an unsecured obligation
of the Guarantor and will rank (i) subordinate and junior in right of payment to
all other liabilities of the Guarantor including the Debentures, except those
liabilities of the Guarantor made pari passu or subordinate by their terms, (ii)
pari passu with the most senior preferred or preference stock now or hereafter
issued by the Guarantor and with any guarantee now or hereafter entered into by
the Guarantor in respect of any preferred or preference stock of any Affiliate
of the Guarantor, and (iii) senior to the Guarantor's common stock.

                             ARTICLE VII TERMINATION

SECTION 7.1   Termination

     This Preferred Securities Guarantee shall terminate (i) upon full payment
of the Redemption Price of all Preferred Securities, (ii) upon the distribution
of the Debentures to the Holders of all of the Preferred Securities or (iii)
upon full payment of the amounts payable in accordance with the Declaration upon
liquidation of the Issuer. Notwithstanding the foregoing, this Preferred
Securities Guarantee will continue to be effective or will be reinstated, as the
case may be, if at any time any Holder of Preferred Securities must restore
payment of any sums paid under the Preferred Securities or under this Preferred
Securities Guarantee.

                          ARTICLE VIII INDEMNIFICATION

SECTION 8.1   Exculpation

     (a)  No Indemnified Person shall be liable, responsible or accountable in
damages or otherwise to the Guarantor or any Covered Person for any loss, damage
or claim incurred by reason of any act or omission performed or omitted by such
Indemnified Person in good faith in accordance with this Preferred Securities
Guarantee and in a manner that such Indemnified Person reasonably believed to be
within the scope of the authority conferred on such Indemnified Person by this
Preferred Securities Guarantee or by law, except that an Indemnified Person
shall be

                                      -17-

<PAGE>

liable for any such loss, damage or claim incurred by reason of such Indemnified
Person's gross negligence or willful misconduct with respect to such acts or
omissions.

     (b)  An Indemnified Person shall be fully protected in relying in good
faith upon the records of the Guarantor and upon such information, opinions,
reports or statements presented to the Guarantor by any Person as to matters the
Indemnified Person 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 Guarantor, 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 Preferred Securities might properly be paid.

SECTION 8.2   Indemnification

     The Guarantor agrees to indemnify each Indemnified Person for, and to hold
each Indemnified Person harmless against, any loss, liability or expense
incurred without gross negligence or bad faith on its part, arising out of or in
connection with the acceptance or administration of the trust or trusts
hereunder, including the costs and expenses (including reasonable legal fees and
expenses) of defending itself against, or investigating, any claim or liability
in connection with the exercise or performance of any of its powers or duties
hereunder. The obligation to indemnify as set forth in this Section 8.2 shall
survive the termination of this Preferred Securities Guarantee or the
resignation or removal of the Preferred Guarantee Trustee.

                            ARTICLE IX MISCELLANEOUS

SECTION 9.1   Successors and Assigns

     All guarantees and agreements contained in this Preferred Securities
Guarantee shall bind the successors, assigns, receivers, trustees and
representatives of the Guarantor and shall inure to the benefit of the Holders
of the Preferred Securities then outstanding.

SECTION 9.2   Amendments

     Except with respect to any changes that do not adversely affect the rights
of Holders (in which case no consent of Holders will be required), this
Preferred Securities Guarantee may only be amended with the prior approval of
the Holders of at least a Majority in liquidation amount (including the stated
amount that would be paid on redemption, liquidation or otherwise, plus accrued
and unpaid Distributions to the date upon which the voting percentages are
determined) of all the outstanding

                                      -18-

<PAGE>

Preferred Securities. The provisions of Section 12.2 of the Declaration with
respect to meetings of Holders of the Securities apply to the giving of such
approval.

SECTION 9.3   Notices

     All notices provided for in this Preferred Securities Guarantee shall be in
writing, duly signed by the party giving such notice, and shall be delivered,
telecopied or mailed by registered or certified mail, as follows:

     (a)  If given to the Preferred Guarantee Trustee, at the Preferred
Guarantee Trustee's mailing address set forth below (or such other address as
the Preferred Guarantee Trustee may give notice of to the Holders of the
Preferred Securities):

          _______________________
          _______________________
          _______________________
          Attention: _______________________
          Facsimile: _______________________

     (b)  If given to the Guarantor, at the Guarantor's mailing address set
forth below (or such other address as the Guarantor may give notice of to the
Holders of the Preferred Securities):

          _______________________
          _______________________
          _______________________
          Attention: _______________________
                     _______________________
          Facsimile: _______________________

     (c)  If given to any Holder of Preferred Securities, at the address set
forth on the books and records of the Issuer.

     All such notices shall be deemed to have been given when received in
person, telecopied with receipt confirmed, or mailed by first class mail,
postage prepaid except that if a notice or other document is refused delivery or
cannot be delivered because of a changed address of which no notice was given,
such notice or other document shall be deemed to have been delivered on the date
of such refusal or inability to deliver.

                                      -19-

<PAGE>

SECTION 9.4   Benefit

     This Preferred Securities Guarantee is solely for the benefit of the
Holders of the Preferred Securities and, subject to Section 3.1(a), is not
separately transferable from the Preferred Securities.

SECTION 9.5   Governing Law

     This preferred securities guarantee shall be governed by, and construed and
interpreted in accordance with, the laws of the state of ____________ without
regard to the conflict of law principles thereof.

     THIS PREFERRED SECURITIES GUARANTEE is executed as of the day and year
first above written.

                                   ___________________________, as Guarantor

                                   By: __________________________________
                                       Name:
                                       Title:

                                   ___________________________, as Preferred
                                   Guarantee Trustee

                                   By: ____________________________________
                                       Name:
                                       Title:

                                      -20-<PAGE>

                                                                    Exhibit 4.22

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

                      COMMON SECURITIES GUARANTEE AGREEMENT

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

                           Dated as of ______ __, ____

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

<PAGE>

                                    CONTENTS

<TABLE>
<S>                                                                     <C>
ARTICLE I   DEFINITIONS AND INTERPRETATION ..........................   2

     SECTION 1.1    Definitions and Interpretation ..................   2

ARTICLE II   GUARANTEE ..............................................   3

     SECTION 2.1    Guarantee .......................................   3

     SECTION 2.2    Waiver of Notice and Demand .....................   3

     SECTION 2.3    Obligations Not Affected ........................   3

     SECTION 2.4    Rights of Holders ...............................   4

     SECTION 2.5    Guarantee of Payment ............................   4

     SECTION 2.6    Subrogation .....................................   5

     SECTION 2.7    Independent Obligations .........................   5

ARTICLE III   LIMITATION OF TRANSACTIONS; SUBORDINATION .............   5

     SECTION 3.1    Limitation of Transactions ......................   5

     SECTION 3.2    Ranking .........................................   6

ARTICLE IV   TERMINATION ............................................   6

     SECTION 4.1    Termination .....................................   6

ARTICLE V   MISCELLANEOUS ...........................................   7

     SECTION 5.1    Successors and Assigns ..........................   7

     SECTION 5.2    Amendments ......................................   7

     SECTION 5.3    Notices .........................................   7

     SECTION 5.4    Benefit .........................................   8

     SECTION 5.5    Governing Law ...................................   8
</TABLE>

<PAGE>

                     COMMON SECURITIES GUARANTEE AGREEMENT

               This GUARANTEE AGREEMENT (the "Common Securities Guarantee"),
dated as of _______ ___, ____, is executed and delivered by ________________, a
___________ corporation (the "Guarantor"), for the benefit of the Holders (as
defined herein) from time to time of the Common Securities (as defined herein)
of ______________________, a Delaware statutory business trust (the "Issuer").

               WHEREAS, pursuant to an Amended and Restated Declaration of Trust
(the "Declaration"), dated as of _______ __, _____, among the trustees of the
Issuer named therein, the Guarantor, as sponsor, and the holders from time to
time of undivided beneficial interests in the assets of the Issuer, the Issuer
is issuing on the date hereof ________ common securities, having an aggregate
stated liquidation amount of _________ designated the ______% Trust Originated
Common Securities (the "Common Securities");

               WHEREAS, as incentive for the Holders to purchase the Common
Securities, the Guarantor desires to irrevocably and unconditionally agree, to
the extent set forth in this Common Securities Guarantee, to pay to the Holders
of the Common Securities the Guarantee Payments (as defined herein) and to make
certain other payments on the terms and conditions set forth herein; and

               WHEREAS, the Guarantor is also executing and delivering a
guarantee agreement (the "Preferred Securities Guarantee") in substantially
identical terms to this Common Securities Guarantee for the benefit of the
holders of the Preferred Securities (as defined herein), except that if an Event
of Default (as defined in the Indenture), has occurred and is continuing, the
rights of Holders of the Common Securities to receive Guarantee Payments under
this Common Securities Guarantee are subordinated to the rights of holders of
Preferred Securities to receive Guarantee Payments under the Preferred
Securities Guarantee.

               NOW, THEREFORE, in consideration of the purchase by each Holder
of Common Securities, which purchase the Guarantor hereby agrees shall benefit
the Guarantor, the Guarantor executes and delivers this Common Securities
Guarantee for the benefit of the Holders.

<PAGE>

                    ARTICLE I DEFINITIONS AND INTERPRETATION

SECTION 1.1 Definitions and Interpretation

     In this Common Securities Guarantee, unless the context otherwise requires:

     (a) Capitalized terms used in this Common Securities Guarantee but not
defined in the preamble above have the respective meanings assigned to them in
this Section 1.1;

     (b) Terms defined in the Declaration as of the date of execution of this
Common Securities Guarantee have the same meaning when used in this Common
Securities Guarantee unless otherwise defined in this Common Securities
Guarantee;

     (c) a term defined anywhere in this Common Securities Guarantee has the
same meaning throughout;

     (d) all references to "the Common Securities Guarantee" or "this Common
Securities Guarantee" are to this Common Securities Guarantee modified,
supplemented or amended from time to time;

     (e) all references in this Common Securities Guarantee to Articles and
Sections are to Articles and Sections of this Common Securities Guarantee unless
otherwise specified; and

     (f) a reference to the singular includes the plural and vice
versa.

     "Guarantee Payments" shall mean the following payments or distributions,
without duplication, with respect to the Common Securities, to the extent not
paid or made by the Issuer: (i) any accrued and unpaid Distributions (as defined
in the Declaration) that are required to be paid on such Common Securities to
the extent the Issuer shall have funds available therefor, (ii) the redemption
price, including all accrued and unpaid Distributions to the date of redemption
(the "Redemption Price") to the extent the Issuer has funds available therefor,
with respect to any Common Securities called for redemption by the Issuer, and
(iii) upon a voluntary or involuntary dissolution, winding-up or termination of
the Issuer (other than in connection with the distribution of Debentures to the
Holders in exchange for Common Securities as provided in the Declaration), the
lesser of (a) the aggregate of the liquidation amount and all accrued and unpaid
Distributions on the Common Securities to the date of payment, to the extent the
Issuer shall have funds available therefor, and (b) the amount of assets of the
Issuer remaining available for distribution to

                                       -2-

<PAGE>

Holders in liquidation of the Issuer (in either case, the "Liquidation
Distribution"). If an Event of Default (as defined in the Indenture) has
occurred and is continuing, the rights of Holders of the Common Securities to
receive Guarantee Payments under this Common Securities Guarantee are
subordinated to the rights of holders of Preferred Securities to receive
Guarantee Payments.

     "Holder" shall mean any holder, as registered on the books and records of
the Issuer, of any Common Securities.

     "Preferred Securities" mean the securities representing preferred undivided
beneficial interests in the assets of the Issuer.

                              ARTICLE II GUARANTEE

SECTION 2.1   Guarantee

     The Guarantor irrevocably and unconditionally agrees to pay in full to the
Holders the Guarantee Payments (without duplication of amounts theretofore paid
by the Issuer), as and when due, regardless of any defense, right of set-off or
counterclaim which the Issuer may have or assert. The Guarantor's obligation to
make a Guarantee Payment may be satisfied by direct payment of the required
amounts by the Guarantor to the Holders or by causing the Issuer to pay such
amounts to the Holders.

SECTION 2.2   Waiver of Notice and Demand

     The Guarantor hereby waives notice of acceptance of this Common Securities
Guarantee and of any liability to which it applies or may apply, presentment,
demand for payment, any right to require a proceeding first against the Issuer
or any other Person before proceeding against the Guarantor, protest, notice of
nonpayment, notice of dishonor, notice of redemption and all other notices and
demands.

SECTION 2.3   Obligations Not Affected

     Except as otherwise provided herein, the obligations, covenants, agreements
and duties of the Guarantor under this Common Securities Guarantee shall in no
way be affected or impaired by reason of the happening from time to time of any
of the following:

     (a)  the release or waiver, by operation of law or otherwise, of the
performance or observance by the Issuer of any express or implied agreement,

                                       -3-

<PAGE>

covenant, term or condition relating to the Common Securities to be performed or
observed by the Issuer;

     (b) the extension of time for the payment by the Issuer of all or any
portion of the Distributions, Redemption Price, Liquidation Distribution or any
other sums payable under the terms of the Common Securities or the extension of
time for the performance of any other obligation under, arising out of, or in
connection with, the Common Securities (other than an extension of time for
payment of Distributions, Redemption Price, Liquidation Distribution or other
sum payable that results from the extension of any interest payment period on
the Debentures or any extension of the maturity date of the Debentures permitted
by the Indenture);

     (c) any failure, omission, delay or lack of diligence on the part of the
Holders to enforce, assert or exercise any right, privilege, power or remedy
conferred on the Holders pursuant to the terms of the Common Securities, or any
action on the part of the Issuer granting indulgence or extension of any kind;

     (d) the voluntary or involuntary liquidation, dissolution, sale of any
collateral, receivership, insolvency, bankruptcy, assignment for the benefit of
creditors, reorganization, arrangement, composition or readjustment of debt of,
or other similar proceedings affecting, the Issuer or any of the assets of the
Issuer;

     (e) any invalidity of, or defect or deficiency in, the Common Securities;

     (f) the settlement or compromise of any obligation guaranteed hereby or
hereby incurred; or

     (g) any other circumstance whatsoever that might otherwise constitute a
legal or equitable discharge or defense of a guarantor, it being the intent of
this Section 2.3 that the obligations of the Guarantor hereunder shall be
absolute and unconditional under any and all circumstances.

There shall be no obligation of the Holders to give notice to, or obtain consent
of, the Guarantor with respect to the happening of any of the foregoing.

SECTION 2.4     Rights of Holders

     The Guarantor expressly acknowledges that any Holder of Common Securities
may institute a legal proceeding directly against the Guarantor to enforce its
rights under this Common Securities Guarantee, without first instituting a legal
proceeding against the Issuer or any other Person.

                                       -4-

<PAGE>

SECTION 2.5   Guarantee of Payment

     This Common Securities Guarantee creates a guarantee of payment and not of
collection.

SECTION 2.6   Subrogation

     The Guarantor shall be subrogated to all (if any) rights of the Holders of
Common Securities against the Issuer in respect of any amounts paid to such
Holders by the Guarantor under this Common Securities Guarantee; provided,
however, that the Guarantor shall not (except to the extent required by
mandatory provisions of law) be entitled to enforce or exercise any right that
it may acquire by way of subrogation or any indemnity, reimbursement or other
agreement, in all cases as a result of payment under this Common Securities
Guarantee, if, at the time of any such payment, any amounts are due and unpaid
under this Common Securities Guarantee. If any amount shall be paid to the
Guarantor in violation of the preceding sentence, the Guarantor agrees to hold
such amount in trust for the Holders and to pay over such amount to the Holders.

SECTION 2.7   Independent Obligations

     The Guarantor acknowledges that its obligations hereunder are independent
of the obligations of the Issuer with respect to the Common Securities and that
the Guarantor shall be liable as principal and as debtor hereunder to make
Guarantee Payments pursuant to the terms of this Common Securities Guarantee
notwithstanding the occurrence of any event referred to in subsections (a)
through (g), inclusive, of Section 2.3 hereof.

                     ARTICLE III LIMITATION OF TRANSACTIONS;
                                  SUBORDINATION

SECTION 3.1   Limitation of Transactions

     So long as any Common Securities remain outstanding, if (i) the Guarantor
shall be in default with respect to its Guarantee Payments or other obligations
hereunder, or (ii) there shall have occurred any Event of Default under the
Indenture or an event of default under the Declaration, then (a) the Guarantor
shall not declare or pay any dividend on, or make any distributions with respect
to, or redeem, purchase, acquire or make a liquidation payment with respect to,
any of its capital stock, (b) the Guarantor shall not make any payment of
interest, principal or premium, if any, on or repay, repurchase or redeem any
debt securities (including guarantees) issued by the Guarantor which rank pari
passu with or junior to the Debentures or

                                       -5-

<PAGE>

(c) the Guarantor shall not make any guarantee payments with respect to the
foregoing (other than, with respect to clauses (a), (b) and (c), (i) dividends
or distributions in shares of, or options, warrants or rights to subscribe for
or purchase shares of, common stock of the Guarantor; (ii) any declaration of a
dividend in connection with the implementation of a shareholder's rights plan,
or the issuance of stock under any such plan in the future, or the redemption or
repurchase of any such rights pursuant thereto; (iii) payments under the
Preferred Securities Guarantee Agreement; (iv) as a direct result of, and only
to the extent required in order to avoid the issuance of fractional shares of
capital stock, following a reclassification of the Guarantor's capital stock or
the exchange or conversion of one class or series of the Guarantor's capital
stock for another class or series of the Guarantor's capital stock; and (v) the
purchase of fractional interests in shares of the Guarantor's capital stock
pursuant to the conversion or exchange provisions of such capital stock or the
security being converted or exchanged).

SECTION 3.2   Ranking

     This Common Securities Guarantee will constitute an unsecured obligation of
the Guarantor and will rank (i) subordinate and junior in right of payment to
all other liabilities of the Guarantor, (ii) pari passu with the most senior
preferred or preference stock now or hereafter issued by the Guarantor and with
any guarantee now or hereafter entered into by the Guarantor in respect of any
preferred or preference stock of any Affiliate of the Guarantor, and (iii)
senior to the Guarantor's common stock.

                             ARTICLE IV TERMINATION

SECTION 4.1   Termination

     This Common Securities Guarantee shall terminate (i) upon full payment of
the Redemption Price of all Common Securities, (ii) upon the distribution of the
Debentures to the Holders of all of the Common Securities, or (iii) or upon full
payment of the amounts payable in accordance with the Declaration upon
liquidation of the Issuer. Notwithstanding the foregoing, this Common Securities
Guarantee will continue to be effective or will be reinstated, as the case may
be, if at any time any Holder of Common Securities must restore payment of any
sums paid under the Common Securities or under this Common Securities Guarantee.

                                       -6-

<PAGE>

                             ARTICLE V MISCELLANEOUS

SECTION 5.1   Successors and Assigns

     All guarantees and agreements contained in this Common Securities Guarantee
shall bind the successors, assigns, receivers, trustees and representatives of
the Guarantor and shall inure to the benefit of the Holders of the Common
Securities then outstanding.

SECTION 5.2   Amendments

     Except with respect to any changes which do not adversely affect the rights
of Holders (in which case no consent of Holders will be required), this Common
Securities Guarantee may only be amended with the prior approval of the Holders
of at least a majority in liquidation amount of all the outstanding Common
Securities. The provisions of Section 12.2 of the Declaration with respect to
meetings of Holders of the Securities apply to the giving of such approval.

SECTION 5.3   Notices

     All notices provided for in this Common Securities Guarantee shall be in
writing, duly signed by the party giving such notice, and shall be delivered,
telecopied or mailed by registered or certified mail, as follows:

     (a)  if given to the Issuer, in care of the Regular Trustees at the
          Issuer's mailing address set forth below (or such other address as the
          Issuer may give notice of to the Holders of the Common Securities):

          ____________________________
          ____________________________
          ____________________________
          ____________________________
          Attention:   _______________________
                       _______________________
          Facsimile _______________________

     (b)  if given to the Guarantor, at the Guarantor's mailing address set
          forth below (or such other address as the Guarantor may give notice of
          to the Holders of the Common Securities):

                                       -7-

<PAGE>

          ____________________________
          ____________________________
          ____________________________
          Attention:   _______________________
                       _______________________
          Facsimile _______________________

     (c)  if given to any Holder of Common Securities, at the address set forth
          on the books and records of the Issuer.

     All such notices shall be deemed to have been given when received in
person, telecopied with receipt confirmed, or mailed by first class mail,
postage prepaid except that if a notice or other document is refused delivery or
cannot be delivered because of a changed address of which no notice was given,
such notice or other document shall be deemed to have been delivered on the date
of such refusal or inability to deliver.

SECTION 5.4   Benefit

     This Common Securities Guarantee is solely for the benefit of the Holders
of the Common Securities and is not separately transferable from the Common
Securities.

SECTION 5.5   Governing Law

     This Common Securities Guarantee shall be governed by, and construed and
interpreted in accordance with, the laws of the State of _____________.

         (The remainder of this page has intentionally been left blank)

                                       -8-

<PAGE>

     THIS COMMON SECURITIES GUARANTEE is executed as of the day and year first
above written.

                                        ___________________________ as Guarantor

                                        By: __________________________________
                                            Name:
                                            Title:

                                       -9-

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