Exhibit 4.3


AMEREN CORPORATION


 


Company Order


 


May 15, 2009


 


The Bank of New York
Mellon Trust Company, N.A.


as Trustee


911 Washington Avenue, Suite 300


St. Louis, Missouri 63101


 


Ladies and Gentlemen:


 


Application is hereby made to The Bank of New York Mellon
Trust Company, N.A., a national banking association, as successor trustee (the “Trustee”),
under the Indenture, dated as of December 1, 2001, as amended and supplemented (the “Indenture”),
between Ameren Corporation, a Missouri corporation (the “Company”), and the
Trustee for the authentication and delivery of $425,000,000 aggregate principal
amount of the Company’s 8.875% Senior Notes due 2014 (the “Notes”), pursuant to
the provisions of Article II of the Indenture.  Additional Notes without limitation as to
amount, and without the consent of the holders of the then Outstanding Notes,
may also be authenticated and delivered in the manner provided in Section 2.05
of the Indenture.  All capitalized terms
not defined herein that are defined in the Indenture shall have the same
meaning as used in the Indenture.


 


The Notes will be registered under the Securities Act
of 1933, as amended, and issued in the form of a Global Note registered in the
name of Cede & Co. (as nominee for The Depository Trust Company (“DTC”),
New York, New York, which will act as the Depositary for the Global Note).  Pursuant to Section 2.05(c) of the
Indenture, the Notes will have the terms set forth in the form of Global Note
attached hereto as Exhibit A (which terms are incorporated by reference in
this Company Order).  The Global Note
shall bear the depositary legend in substantially the form set forth in Exhibit A
attached hereto.  The Notes will be
issued only in denominations of $2,000 and in integral multiples of $1,000 in
excess thereof.


 


The Trustee and the Company will have no
responsibility or liability for any aspect of transfers of beneficial interests
in the Notes (which transfers will be conducted pursuant to the customary
procedures of DTC), any records of DTC of beneficial interests or any
transactions between DTC and its participants or between any such participants
and any other beneficial owners or for monitoring, supervising or reviewing of
any thereof.


 


In connection with this Company Order, there are
delivered to you herewith the following:


 

















 


1.               Certified
copies of the resolutions adopted by the Board of Directors of the Company
authorizing this Company Order and the issuance and sale of the Notes by the
Company pursuant to Section 2.05(c)(1) of the Indenture;


 


2.               Opinions
of Counsel addressed to you or in which it is stated that you may rely pursuant
to Section 2.05(c)(2) of the Indenture;


 


3.               Officers’
Certificate pursuant to Section 2.05(c)(3) of the Indenture; and


 


4.               Global
Note (No. R-1) representing the Notes executed on behalf of the Company in
accordance with the terms of Section 2.05(a) of the Indenture,
specifying the terms of the Notes (which terms are incorporated by reference
herein).


 


You are hereby instructed to authenticate the Global
Note representing the Notes and deliver it to The Bank of New York Mellon Trust
Company, N.A., as custodian for DTC.  The
Global Note representing the Notes is to be held for delivery through the
facilities of DTC to the initial purchasers thereof against payment therefor at
the closing in respect of the issuance thereof, such closing to be held at 10:00 a.m.,
New York time, May 15, 2009 at the offices of Morgan, Lewis &
Bockius LLP, New York, New York.


 

















 


Please acknowledge receipt of the Global Note
representing the Notes, the instructions referred to above and the supporting
documentation pursuant to the Indenture referred to above.


 


	
   

  	
  Very truly yours,

  
	
   

  	
   

  
	
   

  	
   

  
	
   

  	
  AMEREN CORPORATION

  
	
   

  	
   

  
	
   

  	
   

  
	
   

  	
  By:

  	
  /s/ Jerre E. Birdsong

  
	
   

  	
   

  	
  Name:

  	
  Jerre E. Birdsong

  
	
   

  	
   

  	
  Title:

  	
  Vice President and Treasurer

  



 


Receipt from the Company of the Global Note
representing the Notes, certain instructions related thereto and the supporting
documentation pursuant to the Indenture in connection with the authentication
and delivery of the Notes is hereby acknowledged.


 


	
   

  	
  THE BANK OF NEW YORK
  MELLON 

  TRUST COMPANY, N.A.,

  
	
   

  	
  as Trustee

  
	
   

  	
   

  
	
   

  	
   

  
	
   

  	
  By:

  	
   /s/ Mary E. Marler

  
	
   

  	
   

  	
  Name:

  	
  Mary E. Marler

  
	
   

  	
   

  	
  Title:

  	
  Vice President

  



 


 


Signature
Page to Company Order


 

















 


EXHIBIT
A


 


FORM OF
GLOBAL NOTE


 


[depositary legend]


 


THIS SECURITY IS REPRESENTED BY A GLOBAL NOTE
REGISTERED IN THE NAME OF THE DEPOSITARY (REFERRED TO HEREIN) OR A NOMINEE
THEREOF AND, UNLESS AND UNTIL IT IS EXCHANGED IN WHOLE FOR THE INDIVIDUAL NOTES
REPRESENTED HEREBY AS PROVIDED IN THE INDENTURE REFERRED TO BELOW, THIS
SECURITY MAY NOT BE TRANSFERRED EXCEPT AS A WHOLE BY THE DEPOSITARY TO A
NOMINEE OF THE DEPOSITARY OR BY A NOMINEE OF THE DEPOSITARY TO THE DEPOSITARY
OR ANOTHER NOMINEE OF THE DEPOSITARY OR BY THE DEPOSITARY OR ANY SUCH NOMINEE
TO A SUCCESSOR DEPOSITARY OR A NOMINEE OF SUCH SUCCESSOR DEPOSITARY. 
UNLESS THIS SECURITY IS PRESENTED BY AN AUTHORIZED REPRESENTATIVE OF THE
DEPOSITORY TRUST COMPANY (55 WATER STREET, NEW YORK, NEW YORK), TO THE TRUSTEE
FOR REGISTRATION OF TRANSFER, EXCHANGE OR PAYMENT, AND ANY CERTIFICATE ISSUED
IS REGISTERED IN THE NAME OF CEDE & CO. OR SUCH OTHER NAME AS
REQUESTED BY AN AUTHORIZED REPRESENTATIVE OF THE DEPOSITORY TRUST COMPANY AND
ANY PAYMENT IS MADE TO CEDE & CO., ANY TRANSFER, PLEDGE OR OTHER USE
HEREOF FOR VALUE OR OTHERWISE BY OR TO ANY PERSON IS WRONGFUL SINCE THE
REGISTERED OWNER HEREOF, CEDE & CO., HAS AN INTEREST HEREIN.


 


AMEREN CORPORATION

8.875% SENIOR NOTE DUE 2014


 


	
  CUSIP:
  023608 AE2

  	
   

  	
  NUMBER:  R-1

  
	
   

  	
   

  	
   

  
	
  ORIGINAL ISSUE DATE: May 15, 2009

  	
   

  	
  PRINCIPAL AMOUNT:  Listed on Schedule I
  hereto

  
	
   

  	
   

  	
   

  
	
  MATURITY DATE: May 15, 2014

  	
   

  	
   

  



 


AMEREN CORPORATION, a corporation of the State of
Missouri (the “Company”), for value received hereby promises to pay to CEDE &
CO., or registered assigns, the principal amount specified above on the
Maturity Date set forth above, and to pay interest thereon from and including
the Original Issue Date specified above or from and including the most recent
interest payment date to which interest has been paid or duly provided for semi-annually on May 15 and November 15 of each
year, commencing November 15, 2009, and on the Maturity Date
(each, an “Interest
Payment Date”), at the rate of 8.875% per annum (the “Interest Rate”)
until the principal hereof is paid or made available for payment.  No interest shall accrue on the Maturity
Date, so long as the principal amount of this Note is paid in full on the
Maturity Date.


 


The amount of interest payable on any Interest Payment
Date shall be computed on the basis of a 360-day year consisting of twelve 30-day
months.  In the event that any date on
which interest is payable on this Note is not a Business Day, then payment of
interest payable on such date will be made on the next succeeding day that is a
Business Day (and without any interest or other 


 

















 


payment in respect of any such
delay), with the same force and effect as if made on such date.  The interest installment so payable, and
punctually paid or duly provided for, on any Interest Payment Date (except for
interest payable on the Maturity Date or, if applicable, acceleration) will, as
provided in the Indenture (referred to herein), be paid to the person in whose
name this Note is registered at the close of business on the Regular Record
Date for such interest installment, which shall be the May 1 and November 1
as the case may be, next preceding such Interest Payment Date; provided, that
interest payable on the Maturity Date set forth above or, if applicable, upon
acceleration, shall be payable to the Person to whom principal shall be
payable.  Except as otherwise provided in
the Indenture, any such interest not so punctually paid or duly provided for
will forthwith cease to be payable to the Holder on such Regular Record Date
and shall be paid to the Person in whose name this Note is registered at the close
of business on a Special Record Date for the payment of such defaulted interest
to be fixed by the Trustee, notice whereof shall be given to Noteholders not
fewer than ten days prior to such Special Record Date.


 


Payment of the principal of and interest and premium
on this Note shall be payable pursuant to Section 2.12(a) of the
Indenture.


 


This Note is a Global Note issued in respect of a
duly authorized issue of Notes designated “8.875% Senior Notes due 2014” (the “Notes
of this Series”, which term includes any Global Notes representing such Notes)
of the Company issued and to be issued under an Indenture dated as of December 1,
2001 between the Company and The Bank of New York (The Bank of New York Mellon
Trust Company, N.A., successor), as trustee (herein called the “Trustee”, which
term includes any successor Trustee under the Indenture) and indentures
supplemental thereto (collectively, the “Indenture”).  Under the Indenture, one or more series of
notes may be issued and, as used herein, the term “Notes” refers to the Notes
of this Series.  Reference is hereby made
to the Indenture for a more complete statement of the respective rights,
limitations of rights, duties and immunities thereunder of the Company, the
Trustee and the Noteholders and of the terms upon which the Notes are and are
to be authenticated and delivered.


 


Each Note of this Series shall be dated and
issued as of the date of its authentication by the Trustee and shall bear an
Original Issue Date.  Each Note of this Series issued
upon transfer, exchange or substitution of such Note shall bear the Original
Issue Date of such transferred, exchanged or substituted Note, as the case may
be.


 


The Company may, at its option, redeem the Notes in
whole or in part at any time prior to the Maturity Date at the price (the “Redemption
Price”) equal to the greater of (i) 100% of the principal amount of the
Notes being redeemed on the date fixed for redemption (the “Redemption Date”),
or (ii) the sum of the present values of the remaining scheduled payments
of principal and interest on the Notes being redeemed on the Redemption Date
(not including any portion of any payments of interest accrued to the
Redemption Date) discounted to the Redemption Date on a semiannual basis at the
Adjusted Treasury Rate (as defined below) plus 50 basis points, as determined
by the Reference Treasury Dealer (as defined below); plus, in each case,
accrued and unpaid interest thereon to the Redemption Date.  The Redemption Price will be calculated on
the basis of a 360-day year consisting of twelve 30-day months.


 


“Adjusted Treasury Rate”
means, with respect to any Redemption Date, the rate per annum equal to the
semiannual equivalent yield to maturity of the Comparable Treasury Issue,
assuming a 


 


3

















 


price for the Comparable Treasury Issue (expressed
as a percentage of its principal amount) equal to the Comparable Treasury Price
for such Redemption Date.


 


“Comparable Treasury Issue”
means the U.S. Treasury security selected by the Reference Treasury Dealer as
having a maturity comparable to the remaining term of the Notes to be redeemed
that would be utilized, at the time of selection and in accordance with
customary financial practice, in pricing new issues of corporate debt securities
of comparable maturity to the remaining term of such Notes.


 


“Comparable Treasury Price”
means, with respect to any Redemption Date, (A) the average of the
Reference Treasury Dealer Quotations for such Redemption Date, after excluding
the highest and lowest of such Reference Treasury Dealer Quotations, or (B) if
the Trustee obtains fewer than four such Reference Treasury Dealer Quotations,
the average of all such quotations, or (C) if only one Reference Treasury
Dealer Quotation is received, such quotation.


 


“Reference Treasury Dealer”
means (A) BNP Paribas Securities Corp., J.P. Morgan Securities Inc. or UBS
Securities LLC or their respective affiliates which are primary U.S. Government
securities dealers in the United States (each, a “Primary Treasury Dealer”),
and their respective successors; provided, however, that if any of the
foregoing shall cease to be a Primary Treasury Dealer, the Company will
substitute therefor another Primary Treasury Dealer; and (B) any other
Primary Treasury Dealer(s) selected by the Company.


 


“Reference Treasury Dealer
Quotations” means, with respect to each Reference Treasury Dealer
and any Redemption Date, the average, as determined by the Trustee, of the bid
and asked prices for the Comparable Treasury Issue (expressed in each case as a
percentage of its principal amount) quoted in writing to the Trustee by such
Reference Treasury Dealer at 5:00 p.m. (New York City time) on the third
Business Day preceding such Redemption Date.


 


Notice of any redemption will be mailed at least 30
days, but not more than 60 days, before the Redemption Date to each registered
Holder of Notes of this Series to be redeemed at its registered address as
more fully provided in the Indenture. 
Any notice of redemption may state that such redemption will be
conditional upon receipt by the Trustee, on or prior to the Redemption Date, of
money sufficient to pay the principal of and premium, if any, and interest on,
such Notes and that if such money has not been so received, such notice will be
of no force and effect and the Company will not be required to redeem the
Notes.


 


If less than all the Notes are to be redeemed, the
Notes to be redeemed will be selected by the Trustee in such manner as it shall
deem appropriate.


 


The Notes do not have the benefit of any sinking
fund obligation.


 


The Company, at its option, and subject to the terms
and conditions provided in the Indenture, will be discharged from any and all
obligations in respect of the Notes (except for certain obligations including
obligations to register the transfer or exchange of Notes, replace stolen, lost
or mutilated Notes, maintain paying agencies and hold monies for payment in
trust, all as set forth in the Indenture) if the Company deposits with the
Trustee money, U.S. Government Obligations, which through the payment of
interest thereon and principal thereof in accordance with their terms will
provide money, or a combination of money and U.S. Government 


 


4

















 


Obligations, in any event in an amount sufficient,
without reinvestment, to pay all the principal of and any premium and interest
on the Notes on the dates such payments are due in accordance with the terms of
the Notes.


 


If an Event of Default shall
occur and be continuing with respect to the Notes, the principal of and
interest on the Notes may be declared due and payable in the manner and with
the effect provided in the Indenture.


 


The Indenture permits, with
certain exceptions as therein provided, the amendment thereof and the
modifications of the rights and obligations of the Company and the rights of
the Noteholders under the Indenture at any time by the Company and the Trustee
with the consent of the Holders of a majority in aggregate principal amount of
the Outstanding Notes, considered as one class, provided that if a
proposed amendment directly affects the rights of the Holders of Notes of one
or more, but less than all, of series of Outstanding Notes, then with the
consent only of the Holders of a majority in aggregate principal amount of the
Outstanding Notes of all series so directly affected, considered as one class.  Any
such consent or waiver by the Holder of this Note shall be conclusive and
binding upon such Holder and upon all future Holders of this Note and of any
Note issued upon the registration of transfer hereof or in exchange therefor or
in lieu thereof whether or not notation of such consent or waiver is made upon
this Note.


 


As set forth in and subject
to the provisions of the Indenture, no Holder of any Notes issued under the
Indenture will have any right to institute any proceeding with respect to the
Indenture or for any remedy thereunder unless such Holder shall have previously
given to the Trustee written notice of a continuing Event of Default with respect
to such Notes, the Holders of a majority in aggregate principal amount of the
Outstanding Notes of all series under the Indenture in respect of which an
Event of Default has occurred and is continuing, considered as one class, shall
have made written request and offered reasonable indemnity to the Trustee to
institute such proceeding as Trustee and the Trustee shall have failed to
institute such proceeding within 60 days; provided, however, that such
limitations do not apply to a suit instituted by the Holder hereof for the
enforcement of payment of the principal of and any premium or interest on this
Note on or after the respective due dates expressed herein.


 


No reference herein to the
Indenture and to provisions of this Note or of the Indenture shall alter or
impair the obligation of the Company, which is absolute and unconditional, to
pay the principal of and any premium and interest on this Note at the times,
places and rates and the coin or currency prescribed in the Indenture.


 


As provided in the Indenture
and subject to certain limitations therein set forth, this Note may be
transferred only as permitted by the legend hereto and the provisions of the
Indenture.


 


The Indenture and the Notes shall be governed by and
deemed to be a contract under, and construed in accordance with, the laws of
the State of New York, and for all purposes shall be construed in accordance
with the laws of said State without regard to conflicts of law principles
thereof.


 


5

















 


Unless the certificate of
authentication hereon has been executed by the Trustee, directly or through an
Authenticating Agent by manual signature of an authorized officer, this Note
shall not be entitled to any benefit under the Indenture or be valid or obligatory
for any purpose.


 


All terms used in this Note
that are defined in the Indenture shall have the meanings assigned to them in
the Indenture unless otherwise indicated herein.


 


6

















 


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


 


 


	
   

  	
  AMEREN CORPORATION

  
	
   

  	
   

  
	
   

  	
   

  
	
   

  	
  By:

  	
   

  
	
   

  	
  Name:

  
	
   

  	
  Title:

  
	
   

  	
   

  
	
   

  	
   

  
	
  Attest

  	
   

  
	
   

  	
   

  
	
  By:

  	
   

  	
   

  
	
   

  	
   

  
	
  Name:

  	
   

  
	
   

  	
   

  
	
  Title:

  	
   

  
				



 


TRUSTEE’S
CERTIFICATE OF AUTHENTICATION


 


Dated:


 


This Note is one of the Notes
of the series herein designated, described or provided for in the within-mentioned
Indenture.


 


 


	
   

  	
  THE BANK OF NEW YORK MELLON TRUST 

  COMPANY, N.A., As Trustee

  
	
   

  	
   

  
	
   

  	
  By:

  	
   

  
	
   

  	
  Authorized
  Signatory

  



 

















 


ASSIGNMENT


 


FOR VALUE RECEIVED, the
undersigned assigns and transfers this Note to:


 


 


 


 


(Insert assignee’s social security or tax
identification number)


 


 


 


 


(Insert address and zip code of assignee)


 


and irrevocably appoints


 


 


 


 


 


agent to transfer this Note
on the books of the Note register.  The
agent may substitute another to act for him or her.


 


	
  Date:

  	
   

  	
   

  	
   

  
	
   

  	
   

  
	
  Signature:

  	
   

  
	
   

  	
   

  
	
  Signature Guarantee:

  	
   

  



 


 


(Sign exactly as your name appears on the other side of this Security)


 


SIGNATURE GUARANTEE


 


Signatures must be
guaranteed by an “eligible guarantor institution” meeting the requirements of
the Registrar, which requirements include membership or participation in the
Security Transfer Agent Medallion Program (“STAMP”) or such other “signature
guarantee program” as may be determined by the Registrar in addition to, or in
substitution for, STAMP, all in accordance with the Securities Exchange Act of
1934, as amended.


 


8

















 


SCHEDULE I


 


GLOBAL NOTE


 


The initial principal
amount of the Notes evidenced by this Global Note is $                      ;


 


CHANGES TO PRINCIPAL
AMOUNT OF NOTES EVIDENCED BY GLOBAL NOTE


 


	
  Date

  	
   

  	
  Principal Amount of 

  Notes by which this 

  Global Note is to be 

  Reduced or Increased, 

  and Reason for 

  Reduction or Increase

  	
   

  	
  Remaining Principal 

  Amount of Notes 

  Represented by this 

  Global Note

  	
   

  	
  Notation Made by