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                                                                    Exhibit 4.12
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                                    FORM OF


                    PREFERRED SECURITIES GUARANTEE AGREEMENT


                                  DYNEGY INC.


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                            Dated as of ______, ___
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                               TABLE OF CONTENTS

<TABLE>
                                   ARTICLE I
                         DEFINITIONS AND INTERPRETATION
<S>                                                                          <C>
Section 1.1    DEFINITIONS AND INTERPRETATION...............................  1

                                   ARTICLE II
                              TRUST INDENTURE ACT

Section 2.1    TRUST INDENTURE ACT; APPLICATION.............................  5
Section 2.2    LISTS OF HOLDERS OF SECURITIES...............................  5
Section 2.3    REPORTS BY THE PREFERRED SECURITIES GUARANTEE
               TRUSTEE......................................................  5
Section 2.4    PERIODIC REPORTS TO PREFERRED SECURITIES
               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
Section 2.9    PREFERRED SECURITIES GUARANTEE TRUSTEE MAY
               FILE PROOFS OF CLAIM.........................................  7

                                  ARTICLE III
                           POWERS, DUTIES AND RIGHTS
                   OF PREFERRED SECURITIES GUARANTEE TRUSTEE

Section 3.1    POWERS AND DUTIES OF THE PREFERRED SECURITIES
               GUARANTEE TRUSTEE............................................  7
Section 3.2    CERTAIN RIGHTS OF PREFERRED SECURITIES
               GUARANTEE TRUSTEE............................................  8
SECTION 3.3    NOT RESPONSIBLE FOR RECITALS OR ISSUANCE OF
               PREFERRED SECURITIES GUARANTEE............................... 10

                                   ARTICLE IV
                     PREFERRED SECURITIES GUARANTEE TRUSTEE

Section 4.1    PREFERRED SECURITIES GUARANTEE TRUSTEE;
               ELIGIBILITY.................................................. 11

Section 4.2    APPOINTMENT, REMOVAL AND RESIGNATION OF
               PREFERRED SECURITIES GUARANTEE TRUSTEE....................... 11

                                   ARTICLE V
                                   GUARANTEE

Section 5.1    GUARANTEE.................................................... 12
</TABLE>

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<TABLE>
<S>                                                                          <C>
Section 5.2    WAIVER OF NOTICE AND DEMAND.................................. 12
Section 5.3    OBLIGATIONS NOT AFFECTED..................................... 12
Section 5.4    RIGHTS OF HOLDERS............................................ 13
Section 5.5    GUARANTEE OF PAYMENT......................................... 14
Section 5.6    SUBROGATION.................................................. 14
Section 5.7    INDEPENDENT OBLIGATIONS...................................... 14

                                   ARTICLE VI
                   LIMITATION OF TRANSACTIONS; SUBORDINATION

Section 6.1    LIMITATION OF TRANSACTIONS................................... 14
Section 6.2    RANKING...................................................... 15

                                  ARTICLE VII
                                  TERMINATION

Section 7.1    TERMINATION.................................................. 15

                                  ARTICLE VIII
                                INDEMNIFICATION

Section 8.1    EXCULPATION.................................................. 16
Section 8.2    INDEMNIFICATION.............................................. 16

                                   ARTICLE IX
                                 MISCELLANEOUS

Section 9.1    SUCCESSORS AND ASSIGNS....................................... 16
Section 9.2    AMENDMENTS................................................... 17
Section 9.3    NOTICES...................................................... 17
Section 9.4    BENEFIT...................................................... 18
Section 9.5    GOVERNING LAW................................................ 18
Section 9.6    LIMITED LIABILITY............................................ 18
</TABLE>

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                    PREFERRED SECURITIES GUARANTEE AGREEMENT

     THIS GUARANTEE AGREEMENT (the "Preferred Securities Guarantee"), dated as
of ______, ___, is executed and delivered by Dynegy Inc., an Illinois
corporation (the "Guarantor"), and Bank One Trust Company, National Association,
a national banking association, as trustee (the "Preferred Securities Guarantee
Trustee"), for the benefit of the Holders (as defined herein) from time to time
of the Preferred Securities (as defined herein) of Dynegy Capital Trust III, a
Delaware statutory business trust (the "Issuer").

     WHEREAS, pursuant to the Declaration (as defined herein) the Issuer is
issuing on the date hereof $______ aggregate liquidation amount of its ____%
Preferred Securities (collectively the "Preferred Securities") liquidation
amount $1,000 per Preferred Security.

     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 the
Guarantee Payments (as defined below) and to make certain other payments on the
terms and conditions set forth herein.

     WHEREAS, the Guarantor is executing and delivering a guarantee agreement
(the "Common Securities Guarantee"), with 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 Declaration) 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 extent and in the manner set forth in the
Common Securities Guarantee, 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, which
purchase the Guarantor hereby acknowledges shall benefit the Guarantor, the
Guarantor executes and delivers this Preferred Securities Guarantee for the
benefit of the Holders.

                                   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)  terms defined in the Declaration as at the date of execution of this
Preferred Securities Guarantee have the same meaning when used in this Preferred
Securities Guarantee unless otherwise defined in this Preferred Securities
Guarantee;

     (c)  a term defined anywhere in this Preferred Securities Guarantee has the
same meaning throughout;
<PAGE>

     (d)  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;

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

     (f)  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

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

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

     "Business Day" means any day other than a Saturday or a Sunday, or a day on
which banking institutions in Chicago, Illinois or Houston, Texas are authorized
or required by law or executive order to close.

     "Preferred Securities Guarantee Trustee" means Bank One Trust Company,
National Association, a national banking association, until a Successor
Preferred Securities Guarantee Trustee has been appointed and has accepted such
appointment pursuant to the terms of this Preferred Securities Guarantee and
thereafter means each such Successor Preferred Securities Guarantee Trustee.

     "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 Securities
Guarantee Trustee at which the corporate trust business of the Preferred
Securities Guarantee Trustee shall, at any particular time, be principally
administered, which office at the date of execution of this Agreement is located
at 1 Bank One Plaza, Suite IL1-0126, Chicago, Illinois 60670-0126.

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

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

     "Declaration" means the Amended and Restated Declaration of Trust, dated as
of ______, ___, as amended, modified or supplemented from time to time, among
the trustees of the Issuer named therein, the Guarantor, as sponsor, and the
holders from time to time of undivided beneficial ownership interests in the
assets 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, provided,
however, that with respect to a default other than a default in payment of any
Guarantee Payment, the Guarantor shall have

                                      -2-
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received notice of such default and shall not have cured such default within 60
days after receipt of such notice.

     "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 accumulated and unpaid Distributions (as defined in
the Declaration) that are required to be paid on such Preferred Securities to
the extent the Issuer has funds on hand legally available therefor at such time,
(ii) the redemption price, including all accumulated and unpaid Distributions to
the date of redemption (the "Redemption Price") to the extent the Issuer has
funds on hand legally available therefor at such time, with respect to any
Preferred Securities called for redemption by the Issuer, and (iii) upon a
voluntary or involuntary dissolution, winding up or liquidation 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 accumulated and unpaid
Distributions on the Preferred Securities to the date of payment, to the extent
the Issuer has funds on hand legally available therefor, and (b) the amount of
assets of the Issuer remaining available for distribution to Holders in
liquidation of the Issuer after satisfaction of liabilities to creditors of the
Issuer as required by applicable law. If an Event of Default has occurred and is
continuing, no Guarantee Payments under the Common Securities Guarantee with
respect to the Common Securities or any guarantee payment under any Other Common
Securities Guarantees shall be made until the Holders shall be paid in full the
Guarantee Payments to which they are entitled under this Preferred Securities
Guarantee.

     "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 Person known to a Responsible Officer of the
Preferred Securities Guarantee Trustee to be an Affiliate of the Guarantor and
provided further, that in determining whether the Holders of the requisite
liquidation amount of Preferred Securities have voted on any matter provided for
in the Guarantee, then for the purpose of such determination only (and not for
any other purposes hereunder), if the Preferred Securities remain in the form of
one or more Global Certificates (as defined in the Declaration), the term
"Holders" shall mean the holder of the Global Certificate acting at the
direction of the Preferred Security Beneficial Owners (as defined in the
Declaration).

     "Indemnified Person" means the Preferred Securities Guarantee Trustee, any
Affiliate of the Preferred Securities Guarantee Trustee, or any officers,
directors, shareholders, members, partners, employees, representatives,
nominees, custodians or agents of the Preferred Securities Guarantee Trustee.

     "Indenture" means the Indenture dated as of _______, ___, among the
Guarantor (the "Debenture Issuer") and Bank One Trust Company, National
Association, as trustee (the "Indenture Trustee"), and any indenture
supplemental thereto, pursuant to which the Debentures are to be issued to the
Property Trustee (as defined in the Declaration) of the Issuer.

     "Indenture Event of Default" shall mean any event specified in Section 5.01
of the Indenture.

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     "Majority in liquidation amount of the Preferred Securities" means, except
as provided by the Declaration or by the Trust Indenture Act, a vote by
Holder(s) of more than 50% of the aggregate liquidation amount of all
outstanding Preferred Securities voting separately as a class. In determining
whether the Holders of the requisite amount of the Preferred Securities have
voted, Preferred Securities which are owned by the Guarantor or any Affiliate of
the Guarantor shall be disregarded for the purpose of any such determination
period.

     "Officers' Certificate" means, with respect to the Guarantor, a certificate
signed by any of the Chairman of the Board and Chief Executive Officer, the
President or a Vice President and by the Treasurer, an Assistant Treasurer, the
Secretary or an Assistant Secretary of the Guarantor. Any Officers' Certificate
delivered with respect to compliance with a condition or covenant provided for
in this Preferred Securities Guarantee (other than pursuant to Section 314(d)(4)
of the Trust Indenture Act) shall include:

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

     (b)  a brief statement of the nature and scope of the examination or
investigation undertaken by each officer on behalf of such Person in rendering
the Officers' Certificates.

     (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.

     "Other Common Securities Guarantees" shall have the same meaning as "Other
Guarantees" as defined in the Common Securities Guarantee.

     "Other Debentures" means all junior subordinated debentures issued by the
Guarantor from time to time and sold to trusts to be established by the
Guarantor (if any), in each case similar to the Issuer.

     "Other Guarantees" means all guarantees to be issued by the Guarantor with
respect to capital securities (if any) similar to the Preferred Securities
issued by other trusts to be established by the Guarantor (if any), in each case
similar to the Issuer.

     "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.

     "Responsible Officer" means, with respect to the Preferred Securities
Guarantee Trustee, any officer within the Corporate Trust Office of the
Preferred Securities Guarantee Trustee with direct responsibility for the
administration of this Preferred Securities Guarantee and also means, with
respect to a particular corporate trust matter, any other officer to whom such
matter is referred because of that officer's knowledge of and familiarity with
the particular subject.

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<PAGE>

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

     "Trust Indenture Act" means the Trust Indenture Act of 1939, as amended
from time to time, or any successor legislation.

     "Trust Securities" means the Common Securities and the Preferred
Securities, collectively.

                                  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 Section 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 Securities Guarantee Trustee
(unless the Preferred Securities Guarantee Trustee is otherwise the registrar of
the Preferred Securities) with a list, in such form as the Preferred Securities
Guarantee Trustee may reasonably require, of the names and addresses of the
Holders ("List of Holders") as of such date, (i) within one Business Day after
May 15 and November 15 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
Securities Guarantee Trustee, provided, that the Guarantor shall not be
obligated to provide such List of Holders at any time that the Guarantor
certifies in writing to the Preferred Securities Guarantee Trustee that the List
of Holders does not differ from the most recent List of Holders given to the
Preferred Securities Guarantee Trustee by the Guarantor. The Preferred
Securities Guarantee Trustee may destroy any List of Holders previously given to
it on receipt of a new List of Holders.

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

SECTION 2.3    Reports by the Preferred Securities Guarantee Trustee.

     Within 60 days after _______ of each year, commencing ___ __, ____, the
Preferred Securities Guarantee Trustee shall provide to the Holders 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. The
Preferred Securities Guarantee Trustee shall also comply with the other
requirements of Section 313 of the Trust Indenture Act.

                                      -5-
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SECTION 2.4    Periodic Reports to Preferred Securities Guarantee Trustee.

     The Guarantor shall provide to the Preferred Securities 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; provided that such compliance certificate shall be delivered on
or before 120 days after the end of each fiscal year of the Guarantor. Delivery
of such reports, information and documents to the Preferred Securities Guarantee
Trustee is for informational purposes only and the Preferred Securities
Guarantee Trustee's receipt of such shall not constitute constructive notice of
any information contained therein or determinable from information contained
therein, including the Guarantor's compliance with any of its covenants
hereunder (as to which the Preferred Securities Guarantee Trustee is entitled to
rely exclusively on Officers' Certificates).

SECTION 2.5    Evidence of Compliance with Conditions Precedent.

     The Guarantor shall provide to the Preferred Securities 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 all Holders, 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 Securities Guarantee Trustee shall, within 90 days after
the occurrence of an Event of Default with respect to this Preferred Securities
Guarantee actually known to a Responsible Officer, mail by first class postage
prepaid, to all Holders, notices of all such Events of Default, unless such
defaults have been cured before the giving of such notice, provided, that,
except in the case of default in the payment of any Guarantee Payment, the
Preferred Securities Guarantee Trustee shall be protected in withholding such
notice if and so long as the board of directors, the executive committee, or a
trust committee of directors and/or a Responsible Officer in good faith
determines that the withholding of such notice is in the interests of the
Holders.

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

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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.

SECTION 2.9    Preferred Securities Guarantee Trustee May File Proofs of Claim.

     Upon the occurrence of an Event of Default, the Preferred Securities
Guarantee Trustee is hereby authorized to (a) recover judgment, in its own name
and as trustee of an express trust, against the Guarantor for the whole amount
of any Guarantee, payments remaining unpaid and (b) file such proofs of claim
and other papers or documents as may be necessary or advisable in order to have
its claims and those of the Holders of the Preferred Securities allowed in any
judicial procedures relative to the Guarantor, its creditors or its property.

                                  ARTICLE III
                           POWERS, DUTIES AND RIGHTS
                   OF PREFERRED SECURITIES GUARANTEE TRUSTEE

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

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

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

     (c)  The Preferred Securities 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 Securities
Guarantee Trustee. In case an Event of Default has occurred (that has not been
cured or waived pursuant to Section 2.6) and is actually known to a Responsible
Officer, the Preferred Securities 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.

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<PAGE>

     (d)  No provision of this Preferred Securities Guarantee shall be construed
to relieve the Preferred Securities 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 Securities
Guarantee Trustee shall be determined solely by the express provisions of this
Preferred Securities Guarantee, and the Preferred Securities 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 Securities Guarantee Trustee; and

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

          (iii)  the Preferred Securities 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 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 Securities Guarantee
Trustee, or exercising any trust or power conferred upon the Preferred
Securities Guarantee Trustee under this Preferred Securities Guarantee; and

          (iv)   no provision of this Preferred Securities Guarantee shall
require the Preferred Securities 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 Securities 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 Securities Guarantee
Trustee, against such risk or liability is not reasonably assured to it.

SECTION 3.2    Certain Rights of Preferred Securities Guarantee Trustee.

     (a)  Subject to the provisions of Section 3.1:

                                      -8-
<PAGE>

          (i)    The Preferred Securities 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 may be sufficiently evidenced by an Officers'
Certificate.

          (iii)  Whenever, in the administration of this Preferred Securities
Guarantee, the Preferred Securities Guarantee Trustee shall deem it desirable
that a matter be proved or established before taking, suffering or omitting any
action hereunder, the Preferred Securities 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 receipt of such request, shall be promptly delivered by the Guarantor.

          (iv)   The Preferred Securities 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 Securities Guarantee Trustee may consult with
counsel of its selection, and the 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 Securities 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 Securities 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 Securities Guarantee Trustee
such security and indemnity, reasonably satisfactory to the Preferred Securities
Guarantee Trustee, against the costs, expenses (including attorneys' fees and
expenses and the expenses of the Preferred Securities 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 Securities Guarantee Trustee; provided that,
nothing contained in this Section 3.2(a)(vi) shall be taken to relieve the
Preferred Securities 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 Securities 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 Securities Guarantee

                                      -9-
<PAGE>

Trustee, in its discretion, may make such further inquiry or investigation into
such facts or matters as it may see fit.

          (viii)  The Preferred Securities 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
Securities 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 Securities Guarantee Trustee
or its agents hereunder shall bind the Holders, and the signature of the
Preferred Securities 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 Securities 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 Securities Guarantee Trustee's or its agent's taking such action.

          (x)     Whenever in the administration of this Preferred Securities
Guarantee the Preferred Securities 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 Securities 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.

          (xi)    The Preferred Securities Guarantee Trustee shall not be liable
for any action taken, suffered, or omitted to be taken by it in good faith,
without negligence, and reasonably believed by it to be authorized or within the
discretion or rights or powers conferred upon it by this Preferred Securities
Guarantee.

     (b)  No provision of this Preferred Securities Guarantee shall be deemed to
impose any duty or obligation on the Preferred Securities 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 Securities 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 Securities Guarantee Trustee shall be
construed to be a duty.

SECTION 3.3    Not Responsible for Recitals or Issuance of Preferred Securities
               Guarantee.

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

                                      -10-
<PAGE>

                                  ARTICLE IV
                     PREFERRED SECURITIES GUARANTEE TRUSTEE

SECTION 4.1    Preferred Securities Guarantee Trustee; Eligibility.

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

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

          (ii)  be a corporation 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 corporation 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 Securities Guarantee Trustee shall cease
to be eligible to so act under Section 4.1(a), the Preferred Securities
Guarantee Trustee shall immediately resign in the manner and with the effect set
out in Section 4.2(c).

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

SECTION 4.2    Appointment, Removal and Resignation of Preferred Securities
               Guarantee Trustee.

     (a)  Subject to Section 4.2(b), the Preferred Securities Guarantee Trustee
may be appointed or removed without cause at any time by the Guarantor except
during an Event of Default.

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

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

                                      -11-
<PAGE>

appointment by instrument in writing executed by such Successor Preferred
Securities Guarantee Trustee and delivered to the Guarantor and the resigning
Preferred Securities Guarantee Trustee.

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

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

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

                                   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.

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. 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 make any Guarantee Payment during any extended Interest Payment
Period (as defined in the Indenture) with respect to the Distributions (as
defined in the Declaration) on the Preferred Securities.

SECTION 5.3    Obligations Not Affected.

     The obligations, covenants, agreements and duties of the Guarantor under
this Preferred Securities Guarantee shall be absolute and unconditional and
shall remain in full force and effect until the entire liquidation amount of all
outstanding Preferred Securities shall have been paid

                                      -12-
<PAGE>

and such obligation 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 extension of any interest payment period on
the Debentures permitted by the Indenture);

     (c)  any failure, omission, delay or lack of diligence on the part of the
Property Trustee or the Holders to enforce, assert or exercise any right,
privilege, power or remedy conferred on the Property Trustee or 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 with respect to the
Guarantee Payments 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 any
proceeding for any remedy available to the Preferred Securities Guarantee
Trustee in respect of this Preferred Securities Guarantee or exercising any
trust or power conferred upon the Preferred Securities Guarantee Trustee under
this Preferred Securities Guarantee.

     (b)  If the Preferred Securities Guarantee Trustee fails to enforce such
Preferred Securities Guarantee, any Holder may institute a legal proceeding
directly against the Guarantor

                                      -13-
<PAGE>

to enforce its rights under this Preferred Securities Guarantee, without first
instituting a legal proceeding against the Issuer, the Preferred Securities
Guarantee Trustee or any other person or entity. Notwithstanding the foregoing,
if the Guarantor has failed to make a Guarantee Payment, a Holder may directly
institute a proceeding in such Holder's own name against the Guarantor for
enforcement of the Preferred Securities Guarantee for such payment. The
Guarantor waives any right or remedy to require that any action be brought first
against the Issuer or any other person or entity before proceeding directly
against the Guarantor.

SECTION 5.5    Guarantee of Payment.

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

SECTION 5.6    Subrogation.

     The Guarantor shall be subrogated to all (if any) rights of the Holders
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 (h), 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, the Guarantor shall
not, and shall not permit any subsidiary of the Guarantor to, (i) declare or pay
any dividends or distributions on, or redeem, purchase, acquire, or make a
liquidation payment with respect to, any of the Guarantor's capital stock (which
includes common and preferred stock) (other than (a) dividends or distributions
in shares of, or options, warrants, rights to subscribe for or purchase shares
of, common stock of the Guarantor, (b) any declaration of a dividend in
connection with the implementation of a stockholders' 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, (c) as a result of a
reclassification of the Guarantor's capital stock or the exchange or the
conversion of one class or series of the Guarantor's capital stock for another
class or series of the Guarantor's capital stock, (d) the purchase of fractional
interests in shares of the Guarantor's capital stock pursuant to the

                                      -14-
<PAGE>

conversion or exchange provisions of such capital stock or the security being
converted or exchanged, and (e) purchases of the Guarantor's common stock
related to the issuance of the Guarantor's common stock or rights under any of
the Guarantor's benefit plans for its directors, officers, employees or any of
the Guarantor's dividend reinvestment plans), (ii) make any payment of principal
of, or premium, if any, or interest on or repay, repurchase or redeem any debt
securities of the Guarantor (including any Other Debentures) that rank pari
passu with or junior in right of payment to the Debentures or (iii) make any
guarantee payments with respect to any guarantee (other than payments under the
Preferred Securities Guarantee) by the Guarantor of the debt securities of any
subsidiary of the Guarantor (including Other Guarantees) if such guarantee ranks
pari passu with or junior in right of payment to the Debentures if at such time
(1) there shall have occurred any event of which the Guarantor has actual
knowledge that (a) with the giving of notice or the lapse of time, or both,
would constitute an Indenture Event of Default and (b) in respect of which the
Guarantor shall not have taken reasonable steps to cure, (2) an Indenture Event
of Default shall have occurred and be continuing, (3) if such Debentures are
held by the Property Trustee, the Guarantor shall be in default with respect to
its payment of any obligations under this Preferred Securities Guarantee or (4)
the Guarantor shall have given notice of its election of the exercise of its
right to extend the interest payment period pursuant to Section 16.01 of the
Indenture or such extension period, or any such extension shall have commenced
and be continuing.

     Notwithstanding the foregoing, if an Event of Default has occurred and is
continuing under the Declaration, the rights of the holders of the Common
Securities to receive Guarantee Payments under the Common Securities Guarantee
or any Other Common Securities Guarantee shall be subordinated to the rights of
the holders of the Preferred Securities, to receive payments of all amounts due
and owing to such holders under this Preferred Securities Guarantee or any Other
Guarantee.

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
Senior Indebtedness (as defined in the Indenture), to the same extent and in the
same manner that the Debentures are subordinated to Senior Indebtedness pursuant
to the Indenture, (ii) pari passu with the Debentures, the Other Debentures, the
Common Securities Guarantee and any Other Guarantee and any Other Common
Securities Guarantee, and (iii) senior to the Guarantor's capital stock.

                                  ARTICLE VII
                                  TERMINATION

SECTION 7.1    Termination.

     This Preferred Securities Guarantee shall terminate and be of no further
force and effect (i) upon full payment of the Redemption Price (as defined in
the Declaration) of all Preferred Securities, or (ii) upon liquidation of the
Issuer, the full payment of the amounts payable in accordance with the
Declaration or the distribution of the Debentures to the Holders and the holders
of the Common Securities. 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

                                      -15-
<PAGE>

any Holder 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 liable for any such loss, damage or claim incurred by reason of such
Indemnified Person's 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 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 and all loss, liability, damage,
claim or expense incurred without negligence or bad faith on its part, arising
out of or in connection with the acceptance or administration of the trust or
trusts hereunder, including the costs and expenses (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 provisions in this Section 8.2 shall survive the
termination of this Preferred Securities Guarantee or the resignation or removal
of the Preferred Securities 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
then outstanding.

                                      -16-
<PAGE>

SECTION 9.2    Amendments.

     Except with respect to any changes that do not materially 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 a Majority in liquidation amount of the Preferred Securities
(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). The provisions of the Declaration with
respect to consents to amendments thereof (whether at a meeting or otherwise)
shall 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 first class mail, as follows:

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

     Dynegy Capital Trust III
     c/o Dynegy Inc.
     1000 Louisiana, Suite 5800
     Houston, TX 77002
     Attention: Robert B. Doty, Jr. Administrative Trustee
     Telecopy: (713) 7678322

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

     Bank One Trust Company, National Association
     1 Bank One Plaza, Suite IL1-0126,
     Chicago, Illinois 60670-0126
     Attention: Corporate Trust Services Division
     Telecopy: (312) 4071708

     (c)  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 and the Preferred Securities Guarantee Trustee):

     Dynegy Inc.
     1000 Louisiana, Suite 5800
     Houston, TX 77002
     Attention: Kenneth E. Randolph
     Telecopy: (713) 507-6808

                                      -17-
<PAGE>

     (d)  If given to any Holder, 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 9.4    Benefit.

     This Preferred Securities Guarantee is solely for the benefit of the
Holders 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 NEW YORK.

SECTION 9.6    Limited Liability.

     The Holders of the Preferred Securities, in their capacities as such, shall
not be personally liable for any liabilities or obligations of the Guarantor
arising out of this Preferred Securities Guarantee, and the parties hereby agree
that the Holders of the Preferred Securities, in their capacities as such, shall
be entitled to the same limitation of personal liability extended to the
stockholders of private corporations for profit organized under the General
Corporation Law of the State of Delaware.

                                      -18-
<PAGE>

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

                                      DYNEGY INC., as Guarantor



                                      By:_____________________________
                                      Name: __________________________
                                      Title: _________________________


                                      BANK ONE TRUST COMPANY, NATIONAL
                                      ASSOCIATION,
                                      as Preferred Securities Guarantee
                                      Trustee


                                      By:_____________________________
                                      Name: __________________________
                                      Title: _________________________

                                      -19-