INDENTURE

INDENTURE dated as of the 1st day of December, 2008 (hereinafter sometimes referred to as this “ Supplemental Indenture ”), between CENTRAL ILLINOIS LIGHT COMPANY, a corporation of the State of Illinois hereinafter sometimes called the “ Company ”), party of the first part, and Deutsche Bank Trust Company Americas, a corporation of the State of New York, as successor Trustee (hereinafter sometimes called the “ Trustee ”), party of the second part, under the Indenture of Mortgage and Deed of Trust between Illinois Power Company and Bankers Trust Company (predecessor of Deutsche Bank Trust Company Americas), as Trustee, dated as of April 1, 1933, as amended and supplemented by Indenture between said Illinois Power Company and said Bankers Trust Company (predecessor of Deutsche Bank Trust Company Americas), dated as of June 30, 1933, and as amended, supplemented and assumed by Indenture between the Company and said Bankers Trust Company (predecessor of Deutsche Bank Trust Company Americas), dated as of July 1, 1933, and as amended and supplemented by various Indentures between the Company and said Bankers Trust Company (predecessor of Deutsche Bank Trust Company Americas) bearing subsequent dates (said Indenture of Mortgage and Deed of Trust as amended, supplemented and assumed being hereinafter sometimes referred to as the “ Indenture ”).

WHEREAS , the Indenture provides for the issuance of bonds thereunder in one or more series, the form of which series of bonds to be substantially in the form set forth therein with such insertions, omissions and variations as the Board of Directors of the Company may determine; and

WHEREAS, the Company, by appropriate corporate action in conformity with the terms of the Indenture, has duly determined to create a series of bonds under the Indenture to be designated, respectively, as “First Mortgage Bonds, Senior Notes Series CC” (the “ bonds of the Thirty-Third Series ”), the bonds of such series are to be issued as registered bonds without coupons and are to bear interest as specified in the form of bond of the bonds of the Thirty-Third Series set forth below and are to mature, subject to prior acceleration and redemption, on December 15, 2013; and

WHEREAS , the Company has entered into an Indenture dated as of June 1, 2006 (the “ Senior Note Indenture ”) with The Bank of New York Mellon Trust Company, N.A., as trustee (the “ Senior Note Trustee ”), providing for the issuance from time to time of senior notes thereunder; and

WHEREAS , the Company desires by this Supplemental Indenture to issue to the Senior Note Trustee the bonds of the Thirty-Third Series as security for $150,000,000 aggregate principal amount of the Company’s 8.875% Senior Secured Notes due 2013 (the “Senior Notes”) to be issued under the Senior Note Indenture; and

WHEREAS , the definitive registered bonds without coupons of the bonds of the Thirty-Third Series (certain of the provisions of which may be printed on the reverse side thereof) and the Trustee’s certificate of authentication to be borne by such bonds are to be substantially in the following forms, respectively:

[GENERAL FORM OF REGISTERED BOND OF THE THIRTY-THIRD SERIES]

NOTWITHSTANDING ANY PROVISIONS HEREOF OR IN THE INDENTURE THIS BOND IS NOT
ASSIGNABLE OR TRANSFERABLE EXCEPT AS PERMITTED OR REQUIRED BY SECTION 4.04 OF THE
INDENTURE DATED AS OF JUNE 1, 2006, BETWEEN CENTRAL ILLINOIS LIGHT COMPANY AND THE BANK OF NEW YORK MELLON TRUST COMPANY, N.A., AS TRUSTEE

CENTRAL ILLINOIS LIGHT COMPANY

FIRST MORTGAGE BONDS, SENIOR NOTES
SERIES CC

Illinois Commerce Commission
Identification Nos.:  Ill.  C.C.  6479, 6504 and 6506

CENTRAL ILLINOIS LIGHT COMPANY, a corporation of the State of Illinois (hereinafter called the “ Company ”), for value received, hereby promises to pay to The Bank of New York Mellon Trust Company, N.A., as trustee under the Senior Note Indenture hereinafter referred to, or registered assigns, on December 15, 2013, subject to prior redemption, One Hundred and Fifty Million Dollars in lawful money of the United States of America, and to pay to the registered owner hereof interest thereon in lawful money of the United States of America at the rate of 8.875% per annum from the same dates set forth in the Senior Notes (as defined herein).  Interest on overdue principal, premium, if any, and, to the extent permitted by law, on overdue interest, shall be payable at the interest rate payable on the Senior Notes.  Interest on this bond is payable on the same dates as interest on the Senior Notes, or, if this bond shall be duly called for redemption, until the redemption date, or if the Company shall default in the payment of the principal hereof, until the Company’s obligation to pay principal shall be discharged as provided in the Mortgage (hereinafter mentioned) is paid, until the principal sum is paid in full.  The principal of, premium, if any, and interest on, this bond are payable, in immediately available funds, at the office of the Senior Note Trustee hereinafter referred to.

Under an Indenture dated as of June 1, 2006 (the “ Senior Note Indenture ”) between the Company and The Bank of New York Mellon Trust Company, N.A., as trustee (the “ Senior Note Trustee ”), the Company will issue, concurrently with the issuance of this bond, an issue of notes under the Senior Note Indenture entitled “8.875% Senior Secured Notes due 2013” in the aggregate principal amount of $150,000,000 (the “ Senior Notes ”).  Pursuant to Article IV of the Senior Note Indenture, this bond is issued to the Senior Note Trustee to secure any and all obligations of the Company under the Senior Notes and any other series of senior notes from time to time outstanding under the Senior Note Indenture.  Payment of principal of, or premium, if any, or interest on, the Senior Notes shall constitute payments on this bond as further provided herein and in the Indenture dated as of December 1, 2008 pursuant to which this bond has been issued (the “ Supplemental Indenture ”).

Upon any payment of the principal of, premium, if any, and interest on, all or any portion of the Senior Notes, whether at maturity or prior to maturity by redemption or otherwise or upon

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provision for the payment thereof having been made in accordance with Section 5.01(a) of the Senior Note Indenture, a principal amount of this bond equal to the principal amount of such Senior Notes shall, to the extent of such payment of principal, premium, if any, and interest, be deemed paid and the obligation of the Company thereunder to make such payment shall be discharged to such extent and, in the case of the payment of principal (and premium, if any), such bonds shall be surrendered to the Company for cancellation as provided in Section 4.08 of the Senior Note Indenture.  The Trustee (defined below) may at any time and all times conclusively assume that the obligation of the Company to make payments with respect to the principal of, premium, if any, and interest on, the Senior Notes, so far as such payments at the time have become due, has been fully satisfied and discharged pursuant to the foregoing sentence unless and until the Trustee shall have received a written notice from the Senior Note Trustee signed by one of its officers stating (i) that timely payment of principal of, premium, if any, or interest on, the Senior Notes has not been made, (ii) that the Company is in arrears as to the payments required to be made by it to the Senior Note Trustee pursuant to the Senior Note Indenture, and (iii) the amount of the arrearage.

For purposes of Section 4.09 of the Senior Note Indenture, this bond shall be deemed to be the “Related Series of Senior Note First Mortgage Bonds” in respect of the Senior Notes.

This bond is one of an issue of bonds of the Company, issuable in series, and is one of a series known as its First Mortgage Bonds of the series designated in its title, all issued and to be issued under and equally secured (except as to any sinking fund established in accordance with the provisions of the Mortgage (defined below) for the bonds of any particular series) by an Indenture of Mortgage and Deed of Trust dated as of April 1, 1933, executed by Illinois Power Company to Bankers Trust Company (predecessor of Deutsche Bank Trust Company Americas) or its successor (hereinafter sometimes referred to as the “ Trustee ”) as Trustee, as amended by Indenture dated as of June 30, 1933, as assumed by the Company and as amended and supplemented by Indentures between the Company and the Trustee bearing subsequent dates, including the Supplemental Indenture (all of which indentures are herein collectively called the “ Mortgage ”), to which reference is made for a description of the property mortgaged and pledged, the nature and extent of the security, the rights of the holders of the bonds in respect thereof and the terms and conditions upon which the bonds are secured.

The principal hereof may be declared or may become due on the conditions, with the effect, in the manner and at the time set forth in the Mortgage, upon the occurrence of a completed default as in the Mortgage provided.

This bond is not redeemable except on the date, in the principal amount and for the redemption price that correspond to the redemption date for, the principal amount to be redeemed of, and the redemption price for, the Senior Notes, and except upon written demand of the Senior Note Trustee following the occurrence of an event of default under the Senior Note Indenture and the acceleration of the Senior Notes, as provided in Section 8.01 of the Senior Note Indenture.

In the manner and upon payment of the charges prescribed in the Mortgage, registered bonds without coupons of this series may be exchanged for a like aggregate principal amount of fully registered bonds of other authorized denominations of the same series, upon presentation

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and surrender thereof, for cancellation, to the Trustee at its principal office in the Borough of Manhattan, The City of New York, New York.

This bond shall not be assignable or transferable except as permitted or required by Section 4.04 of the Senior Note Indenture.  Subject to the restriction on transfer of this bond hereinbefore set forth, this bond is transferable as prescribed in the Mortgage by the registered owner hereof in person, or by his duly authorized attorney, at the office or agency of the Company in the Borough of Manhattan, The City of New York, New York, upon surrender and cancellation of this bond, and, thereupon, a new fully registered bond of the same series for a like principal amount will be issued to the transferee in exchange therefor as provided in the Mortgage, and upon payment, if the Company shall require it, of the charges therein prescribed.

No recourse shall be had for the payment of the principal of, premium, if any, or interest on this bond against any incorporator or any past, present or future subscriber to the capital stock, stockholder, officer or director of the Company or of any predecessor or successor corporation, either directly or through the Company or any predecessor or successor corporation, under any rule of law, statute or constitution or by the enforcement of any assessment or otherwise, all such liability of incorporators, subscribers, stockholders, officers and directors being released by the holder or owner hereof by the acceptance of this bond and being likewise waived and released by the terms of the Mortgage.

This bond shall not become obligatory until Deutsche Bank Trust Company Americas, the Trustee under the Mortgage, or its successor thereunder, shall have signed the form of certificate endorsed hereon.

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IN WITNESS WHEREOF, CENTRAL ILLINOIS LIGHT COMPANY has caused this bond to be signed in its name by its President or a Vice President by a facsimile of his signature and a facsimile of its corporate seal to be printed hereon, attested by its Secretary or an Assistant Secretary by a facsimile of his signature.

Dated:

[FORM OF TRUSTEE’S CERTIFICATE]

This bond is one of the bonds of the series designated therein, described in the within mentioned Mortgage.

WHEREAS , all things necessary to make the bonds of the Thirty-Third Series, when authenticated by the Trustee and issued as in the Indenture provided, the valid, binding and legal obligations of the Company, entitled in all respects to the security of the Indenture, have been done and performed, and the creation, execution and delivery of t