Exhibit 4.55


 


SIXTH SUPPLEMENTAL INDENTURE


	
   

  



 


 


SIXTH SUPPLEMENTAL INDENTURE


 


dated as of July 7, 2008


 


to


 


INDENTURE


 


dated as of November 1, 2000


 


AMEREN ENERGY GENERATING COMPANY


 


to


 


THE BANK OF NEW YORK MELLON TRUST COMPANY,
N.A.

(formerly known as THE BANK OF NEW YORK TRUST COMPANY, N.A.), as Trustee


 


	
   

  



 


$300,000,000 7.00% Senior Notes, Series H
Due 2018


 

















 


SIXTH SUPPLEMENTAL INDENTURE (this “Sixth
Supplemental Indenture”), dated as of July 7, 2008, to the Indenture,
dated as of November 1, 2000 (the “Original Indenture”), from AMEREN
ENERGY GENERATING COMPANY, an Illinois corporation (together with its
successors and assigns, the “Issuer”), its principal office and mailing address
being at One Ameren Plaza, 1901 Chouteau Avenue, P.O. Box 66149, St. Louis,
Missouri 63166-6149, to THE BANK OF NEW YORK MELLON TRUST COMPANY, N.A.
(formerly known as THE BANK OF NEW YORK TRUST COMPANY, N.A.), a national
banking association organized and existing under and by virtue of the laws of
the United States, as trustee (the “Trustee”), its office and mailing address
being at 911 Washington Avenue, 3rd Floor St. Louis, Missouri 63101.


 


W I T N E S S E T H:


 


WHEREAS, the Issuer and the Trustee have
heretofore executed and delivered the Original Indenture to provide for the
issuance from time to time of the Issuer’s Securities (as defined in the
Original Indenture) to be issued in one or more series;


 


WHEREAS, Sections 2.1 and 7.1(b) of the
Original Indenture provide, among other things, that the Issuer and the Trustee
may enter into indentures supplemental to the Original Indenture for, among
other things, the purpose of establishing the designation, form, terms and
provisions of Securities of any series as permitted by Sections 2.1 and 7.1(b) of
the Original Indenture;


 


WHEREAS, the Issuer has heretofore issued a
series of Securities designated 7.00% Senior Notes, Series G due 2018 (the
“Old Notes”);


 


WHEREAS, the Old Notes were sold to a group
consisting of Lehman Brothers Inc., UBS Securities LLC and Wachovia Capital Markets,
LLC (collectively, the “Initial Purchasers”);


 


WHEREAS, sales and transfers of the Old Notes
are restricted to qualified institutional investors pursuant to Rule 144A
under the Securities Act of 1933, as amended (the “Securities Act”) and
qualified buyers outside the United States pursuant to Regulation S under the
Securities Act;


 


WHEREAS, the Issuer and the Initial
Purchasers entered into a Registration Rights Agreement, dated as of April 9,
2008 (the “Registration Rights Agreement”), pursuant to which the Issuer
agreed, for the benefit of the Holders of the Old Notes, to file a registration
statement relating to an exchange offer allowing the Holders of the Old Notes
to exchange their transfer restricted Old Notes for a new series of notes that
are identical in all material respects to the Old Notes except that the new
series of notes will not contain the transfer restrictions or registration
rights applicable to the Old Notes, and the new series of notes would be
registered under the Securities Act;


 


WHEREAS, the Issuer (i) desires the
issuance of a series of Securities to be designated as hereinafter provided and
(ii) has requested the Trustee to enter into this Sixth Supplemental
Indenture for the purpose of establishing the designation, form, terms and
provisions of the Securities of such series;


 

















 


WHEREAS, all action on the part of the Issuer
necessary to authorize the issuance of said Securities under the Original
Indenture and this Sixth Supplemental Indenture (the Original Indenture, as
supplemented by this Sixth Supplemental Indenture, being hereinafter called the
“Indenture”) has been duly taken; and


 


WHEREAS, all acts and things necessary to
make said Securities, when executed by the Issuer and authenticated and
delivered by the Trustee as provided in the Original Indenture, the legal,
valid and binding obligations of the Issuer, and to constitute these presents a
valid and binding supplemental indenture according to its terms, have been done
and performed, and the execution of this Sixth Supplemental Indenture and the
creation and issuance under the Indenture of said Securities have in all
respects been duly authorized, and the Issuer, in the exercise of the legal
right and power vested in it, executes this Sixth Supplemental Indenture and proposes
to create, execute, issue and deliver said Securities;


 


NOW, THEREFORE, in order to establish the
designation, form, terms and provisions of, and to authorize the authentication
and delivery of, said Securities, and in consideration of the acceptance of
said Securities by the holders thereof and of other good and valuable
consideration, the receipt and sufficiency of which are hereby acknowledged,
the parties hereto agree as follows:


 


ARTICLE I



DEFINITIONS


 


Capitalized terms not otherwise defined herein
shall have the meanings set forth in the Original Indenture.


 


ARTICLE II



THE TERMS OF THE SERIES H NOTES


 


Section 2.1                                      Terms
of 7.00% Senior Notes, Series H due 2018.  (a)  There is hereby created one (1) series
of Securities designated:  7.00% Senior
Notes, Series H due 2018, in the initial aggregate principal amount of
$300,000,000 (the “Series H Senior Notes”) less the amount of any Old
Notes that remain outstanding and unexchanged following completion of the
Issuer’s exchange offer for the Old Notes as contemplated by its prospectus
dated June 3, 2008.  Upon delivery
of a written order to the Trustee in accordance with the provisions of Section 2.1
of the Original Indenture, the Trustee shall authenticate and deliver the Series H
Senior Notes.  Such written order shall
specify the amount of the Series H Senior Notes to be authenticated and
the date on which such Series H Senior Notes are to be authenticated,
which will be the date on which the Series H Senior Notes are issued in
exchange for the Old Notes.


 


(b)                                 The
Series H Senior Notes shall be substantially in the form of Exhibit A
hereto.


 


2

















 


Section 2.2                                      Terms
of Series H Senior Notes Issued Hereunder in Global Form.


 


(a)                                  So
long as DTC or its nominee is the registered owner or Holder of a Global
Security, DTC or its nominee, as the case may be, will be considered the sole
owner or Holder of the Series H Senior Notes represented by such Global
Security for all purposes under the Original Indenture and under the Series H
Senior Notes.  No beneficial owner of an
interest in a Global Security will be able to transfer that interest except in
accordance with DTC’s applicable procedures unless the Issuer shall issue
certificates for the Series H Senior Notes in definitive registered form.


 


(b)                                 All
payments of the principal of, and interest and additional interest and premium,
if any, on, a Global Security will be made to DTC or its nominees, as the
registered owners thereof.


 


(c)                                  Transfers
between participants in DTC will be effected in the ordinary way in accordance
with DTC rules and will be settled in same-day funds.


 


(d)                                 Certificated
definitive Series H Senior Notes may be in denominations of less than
$100,000 to the extent any redemption has reduced such Holder’s aggregate
holding of such Series H Senior Notes to less than $100,000.


 


(e)                                  If
any redemption affecting the Series H Senior Notes would result in the
amount to be paid to a Holder of such affected Senior Note in respect of such
redemption not to equal $1,000 or an integral multiple thereof (in excess of
$100,000), the Issuer shall instruct the Trustee to round the amount to be paid
to such Holder to the nearest $1,000 so that the amount to be paid to such
Holder equals $1,000 or an integral multiple thereof.


 


(f)                                    Except
in the limited circumstances described under Section 2.2(g) below,
beneficial interests in a Global Security will only be recorded by book-entry,
and owners of beneficial interests in a Global Security will not be entitled to
receive physical delivery of certificates representing Series H Senior
Notes.


 


(g)                                 If
(i) DTC or any successor depository notifies the Issuer that it is
unwilling or unable to continue as a depository for a Global Security or ceases
to be a “clearing agency” registered under the Exchange Act and a successor
depository is not appointed by the Issuer within 90 days of such notice, (ii) an
Event of Default under the Series H Senior Notes has occurred and is
continuing and payment of principal and interest has been accelerated or (iii) the
Issuer decides, at its option, to discontinue use of the book-entry system
through DTC, then the Issuer shall issue certificates for the Series H
Senior Notes in definitive registered form substantially in the form attached
hereto in exchange for the Global Security outstanding.


 


(h)                                 The
holder of a certificated definitive registered Series H Senior Note may
transfer such Series H Senior Note in whole or in part by surrendering it
at the Corporate Trust Office of the Trustee in accordance with the terms of
the Indenture and such Series H Senior Note.


 


Section 2.3                                      Interest,
Principal, Maturity Date and Regular Record Date.  The Series H Senior Notes shall bear
interest on the unpaid principal amount thereof from time to time 


 


3

















 


outstanding
from the date of issuance of the Old Notes or the last interest payment date
through which interest shall have been paid on the Old Notes for which they are
exchanged until such amount is paid in full at the rate of interest set forth
in the form of such Series H Senior Note attached hereto.  The principal amount of the Series H
Senior Notes shall be due and payable at maturity as set forth in the form of Series H
Senior Note attached hereto.


 


Payment of principal, premium, if any, and
interest on the Series H Senior Notes shall be made as provided in
Sections 2.4, 2.10, 3.2 and 3.4 of the Original Indenture, except that the
final payment of principal of the Series H Senior Notes shall be made on
the due date therefor to the account of the Holder as such account shall appear
in the Security Register, which amount shall be payable upon presentation and
surrender of such Series H Senior Note at the office of the Issuer.


 


The Series H Senior Notes shall mature
on the date and in the amounts set forth thereon.


 


The record date applicable to the Series H
Senior Notes issued hereunder shall be as set forth in the form of Series H
Senior Note attached hereto.


 


All payments of principal, premium, if any,
and interest with respect to certificated Series H Senior Notes will be
made by bank check mailed on the interest payment date to the address of such
Holder on the Security Register or, for Holders of at least U.S. $1,000,000 in
aggregate principal amount of Series H Senior Notes, by wire transfer on
the interest payment date of immediately available funds to a dollar account
maintained by such Holder with a bank or other financial institution; provided that a written request from such Holder to such
effect designating such account is received by the Trustee and the Issuer or
the paying agent no later than the record date immediately preceding such
Interest Payment Date.  Unless such
designation is revoked, any such designation made by such person with respect
to such certificated Series H Senior Notes will remain in effect with
respect to any future payments with respect to such certificated Senior Note
payable to such person.


 


Section 2.4                                      Optional
Redemption.  The Series H Senior
Notes issued hereunder are subject to optional redemption, in whole or in part,
at any time at the option of the Issuer at a redemption price equal to 100% of
the outstanding principal amount of the Series H Senior Notes being so
redeemed plus accrued and unpaid interest thereon to the date fixed for
redemption (the “Determination Date”) together with the Applicable Premium
applicable thereto.


 


Section 2.5                                      Reopen
Series.  The Issuer, from time to
time, without the consent of the Holders of the Series H Senior Notes, may
reopen the Series H Senior Notes and create and issue further senior debt
securities under the Indenture having the same terms and conditions (including
the same CUSIP number) as the Series H Senior Notes issued hereunder in
all respects, except for the date of original issuance, the initial interest
payment date and the offering price. 
Such additional senior debt securities shall be consolidated with, and
form a single series with, the previously outstanding Series H Senior
Notes hereunder.


 


4

















 


Section 2.6                                      Applicable
Premium.  As used herein, “Applicable
Premium” means an amount calculated as follows:


 


(a)                                  the
average life of the remaining scheduled payments of principal in respect of
Outstanding Series H Senior Notes (the “Remaining Average Life”) shall be
calculated as of the Determination Date;


 


(b)                                 the
yield to maturity calculated as of a date not more than five days prior to the
Determination Date for the United States Treasury security having an average
life equal to the Remaining Average Life and trading in the secondary market at
the price closest to the principal amount thereof (the “Primary Issue”); provided, however, that
if no United States Treasury security has an average life equal to the
Remaining Average Life, the yields (the “Other Yields”) for the two maturities
of United States Treasury securities having average lives most closely
corresponding to such Remaining Average Life and trading in the secondary
market at the price closest to the principal amount thereof shall be
calculated, and the yield to maturity for the Primary Issue shall be the yield
interpolated or extrapolated from such Other Yields on a straight line basis,
rounding in each of such relevant periods to the nearest month;


 


(c)                                  the
discounted present value of the then-remaining scheduled payments of principal
and interest (but excluding that portion of any scheduled payment of interest
that is actually due and paid on the Determination Date) in respect of the
Outstanding Series H Senior Notes shall be calculated as of the
Determination Date using a discount factor equal to the sum of (x) the
yield to maturity for the Primary Issue, plus (y) 50 basis points;
and


 


(d)                                 the
amount of Applicable Premium in respect of the Series H Senior Notes to be
redeemed shall be an amount equal to (x) the discounted present value of
such Series H Senior Notes to be redeemed determined in accordance with
clause (iii) above, minus (y) the unpaid principal amount of
such Series H Senior Notes; provided, however, that the Applicable Premium shall not be less than
zero; and


 


(e)                                  such
calculation shall be made by an Investment Banker.


 


Section 2.7                                      Amendments
for Benefit of Series H Senior Notes. 
The Indenture is hereby amended, pursuant to Section 7.1(d) of
the Original Indenture for the benefit of the holders of the Series H
Senior Notes and for so long as the Series H Senior Notes are outstanding,
as follows:


 


(a)                                  Section 1.1
of the Original Indenture is amended by adding to the definitions the
following: “‘Existing Generating Assets’, when used in respect of the
$300,000,000 7.00% Senior Notes, Series H due 2018, means the coal-fired
and oil-fired units and gas-fired units owned by the Issuer as of the date of
issuance of such Notes.”


 


(b)                                 Notwithstanding
Section 3.13 of the Original Indenture, the Issuer may not cease to comply
with the covenants of Sections 3.11 and 3.12 of the Original Indenture unless,
in addition to complying with such Section 3.13, the rating on the Series H
Senior Notes from 


 


5

















 


Standard &
Poor’s Ratings Services (or any successor thereto) is at least BBB+ after
giving effect to such cessation.


 


(c)                                  Section 3.9
of the Original Indenture is amended to delete the words “Initial Generation
Assets” and insert in lieu thereof the words “Existing Generating Assets”.


 


(d)                                 Section 4.1(i) of
the Original Indenture is amended to delete the words “Initial Generating
Assets” and insert in lieu thereof the words “Existing Generating Assets”.


 


(e)                                  In
Section 4.1(i) of the Original Indenture, for the avoidance of doubt,
the reference to the “Genco-Marketing Co. PPA” shall be deemed to refer to the
Amended and Restated Power Supply Agreement dated as of March 28, 2008
between the Issuer and Ameren Energy Marketing Company.


 


Section 2.8                                      Registered
Notes Issued Upon Exchange.  The Series H
Senior Notes shall be registered under the Securities Act and the transfer
restrictions set forth in Section 2.6 of the Original Indenture shall not
apply to the transfer of the Series H Senior Notes and the Legend referred
to in Section 2.6 of the Original Indenture shall not be required to be
placed on each certificate representing the Series H Senior Notes.  Pursuant to the Issuer’s written order to the
Trustee in accordance with the provisions of Section 2.1 of the Original
Indenture, the Issuer shall execute and the Trustee shall authenticate and
deliver Series H Senior Notes in denominations of $100,000 original
principal amount in exchange for each $100,000 principal amount of outstanding
Old Notes, and in integral multiples of $1,000 original principal amount in
exchange for each $1,000 in excess thereof if properly tendered by the Holder
thereof together with a completed letter of transmittal in the form attached
hereto as Exhibit B, which is incorporated herein by this reference.  Upon the surrender of any Old Notes as
contemplated herein, such Old Notes shall be cancelled by the Trustee and no
further amounts shall be due and payable on such Old Notes (except that any
accrued but unpaid liquidated damages due pursuant to the Registration Rights
Agreement shall remain due and payable) and any interest accrued and unpaid on
the Old Notes through the date of such exchange, which shall be the date of
authentication of the Series H Senior Notes, shall from and after such
exchange be represented by the Series H Senior Notes and shall be payable
as provided in the Series H Senior Notes. 
Interest shall accrue on the Series H Senior Notes as described in Section 2.3
hereof; provided that the amount payable on the Series H Senior Notes
pursuant to Section 2.3 will be offset by the amount of interest accrued
on the Old Notes prior to the date of exchange which is thereafter deemed
payable on the Series H Senior Notes under this Section 2.8.


 


Section 2.9                                      Treatment
of Series.  For all purposes of the
Indenture, the Old Notes and the Series H Senior Notes shall be treated as
the same series and the Holders of the Old Notes and the Series H Senior
Notes shall vote and consent together on all matters as one class and none of
the Holders of the Old Notes or the Series H Senior Notes shall have the
right to vote or consent as a separate class on any matter.


 


6

















 


ARTICLE III



MISCELLANEOUS


 


Section 3.1                                      Execution
of Supplemental Indenture.  This
Sixth Supplemental Indenture is executed and shall be construed as an indenture
supplemental to the Original Indenture and, as provided in the Original
Indenture, this Sixth Supplemental Indenture forms a part thereof.


 


Section 3.2                                      Concerning
the Trustee.  The Trustee shall not
be responsible in any manner for or with respect to the validity or sufficiency
of this Sixth Supplemental Indenture, or the due execution hereof by the
Issuer, or for or with respect to the recitals and statements contained herein,
all of which recitals and statements are made solely by the Issuer.


 


Section 3.3                                      Counterparts.  This Sixth Supplemental Indenture may be
executed in any number of counterparts, each of which when so executed shall be
deemed to be an original; but all such counterparts shall together constitute
but one and the same instrument.


 


Section 3.4                                      GOVERNING
LAW.  THIS SIXTH SUPPLEMENTAL
INDENTURE AND THE SERIES H SENIOR NOTES ISSUED HEREUNDER SHALL, PURSUANT TO SECTION 5-1401
OF THE NEW YORK GENERAL OBLIGATIONS LAW, BE GOVERNED BY THE LAW OF THE STATE OF
NEW YORK, WITHOUT REFERENCE TO THE CHOICE OF LAW PROVISIONS THEREOF (OTHER THAN
SUCH SECTION 5-1401).


 


7

















 


IN WITNESS WHEREOF, the parties hereto have
caused this Sixth Supplemental Indenture to be duly executed as of July 7,
2008.


 


	
   

  	
  AMEREN ENERGY GENERATING

  
	
   

  	
  COMPANY, as
  Issuer 

  
	
   

  	
   

  
	
   

  	
   

  
	
   

  	
  By:

  	
  /s/ Bruce A. Steinke

  
	
   

  	
   

  	
  Name: Bruce A. Steinke 

  
	
   

  	
   

  	
  Title: Vice President and Controller

  
	
   

  	
   

  
	
   

  	
  THE BANK OF NEW YORK MELLON

  TRUST COMPANY, N.A. (formerly known as

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

  as Trustee

  
	
   

  	
   

  
	
   

  	
   

  
	
   

  	
  By:

  	
  /s/ Mary E. Marler

  
	
   

  	
   

  	
  Name: Mary E. Marler

  
	
   

  	
   

  	
  Title: Vice President

  



 
















 


EXHIBIT A


 


FORM OF SECURITY


 


UNLESS THIS CERTIFICATE IS
PRESENTED BY AN AUTHORIZED REPRESENTATIVE OF THE DEPOSITORY TRUST COMPANY TO
THE ISSUER OR ITS AGENT FOR REGISTRATION OF TRANSFER, EXCHANGE OR PAYMENT, AND
ANY CERTIFICATE ISSUED IN EXCHANGE FOR THIS CERTIFICATE OR ANY PORTION HEREOF
IS REGISTERED IN THE NAME OF CEDE & CO. OR TO SUCH OTHER ENTITY AS IS
REQUESTED BY AN AUTHORIZED REPRESENTATIVE OF THE DEPOSITORY TRUST COMPANY OR
SUCH OTHER NAME AS IS REQUESTED BY AN AUTHORIZED REPRESENTATIVE OF THE DEPOSITORY
TRUST COMPANY (AND ANY PAYMENT HEREON IS MADE TO CEDE & CO.), ANY
TRANSFER, PLEDGE OR OTHER USE HEREOF FOR VALUE OR OTHERWISE BY OR TO ANY PERSON
OTHER THAN THE DEPOSITORY TRUST COMPANY OR A NOMINEE THEREOF IS WRONGFUL
INASMUCH AS THE REGISTERED OWNER HEREOF, CEDE & CO., HAS AN INTEREST
HEREIN.


 


TRANSFERS OF THIS GLOBAL
SECURITY SHALL BE LIMITED TO TRANSFERS IN WHOLE, BUT NOT IN PART, TO NOMINEES
OF THE DEPOSITORY TRUST COMPANY OR TO A SUCCESSOR THEREOF OR SUCH SUCCESSOR’S
NOMINEE AND TRANSFERS OF PORTIONS OF THIS GLOBAL SECURITY SHALL BE LIMITED TO
TRANSFERS MADE IN ACCORDANCE WITH THE RESTRICTIONS SET FORTH IN SECTION 2.6
OF THE INDENTURE REFERRED TO ON THE REVERSE HEREOF.


 

















 


[FORM OF FACE OF SERIES H SENIOR NOTE]


 


CUSIP 


[           ][           ][           ]


 


[Common Code]


[ISIN][           ]


 


No.


 


$

AMEREN ENERGY GENERATING COMPANY

7.00% Senior Notes, Series H Due 2018


 


Ameren Energy Generating Company (the “Issuer”),
for value received hereby promises to pay to
                                      
or registered assigns the principal sum of
                        
Dollars at the Issuer’s office or agency for said purpose as provided in the
Indenture referred to herein, on April 15, 2018 in such coin or currency
of the United States of America as at the time of payment shall be legal tender
for the payment of public and private debts, and to pay interest, semi-annually
in arrears on April 15 and October 15 of each year, commencing October 15,
2008, on said principal sum in like coin or currency at the rate per annum set
forth above at said offices or agencies from the date of original issuance or
the most recent interest payment date to which interest on the 7.00% Senior
Notes, Series H due 2018 (the “Series H Senior Notes”) has
been paid or duly provided for. 
Notwithstanding the foregoing, if the date hereof is after April 1
or October 1, as the case may be, and before the following April 15
or October 15, this Senior Note shall bear interest from such April 15
or October 15; provided, that if the Issuer shall default in the payment
of interest due on such April 15 or October 15, then this Senior Note
shall bear interest from the next preceding April 15 or October 15 to
which interest on the Series H Senior Notes has been paid or duly provided
for and provided further that interest due on October 15, 2008 on this
Senior Note shall accrue from the date of original issuance of the Issuer’s
7.00% Senior Notes, Series G due 2018 (the “Old Notes”).  The interest so payable on any April 15
or October 15 will, except as otherwise provided in the Indenture referred
to on the reverse hereof, be paid to the Person in whose name this Senior Note
is registered at the close of business on the 1st day of April or the 1st
day of October preceding such April 15 or October 15, whether or
not such day is a Business Day; provided, that principal, premium, if any, and
interest shall be paid by mailing on the interest payment date a check for such
to or upon the written order of the registered Holders of Series H Senior
Notes entitled thereto at their last address as it appears on the Series H
Senior Notes Register or, upon written application to the Trustee by a Holder
of $1,000,000 or more in aggregate principal amount of Series H Senior
Notes, by wire transfer on the interest payment date of immediately available
funds to an account maintained by such Holder with a bank or other financial
institution.  Interest on this Senior
Note shall be computed on the basis of a 360-day year comprised of twelve
30-day months.  Additional Interest (as
defined in the Registration Rights Agreement) shall accrue on this Senior Note
under the circumstances provided for in the Registration Rights Agreement.


 

















 


Interest on overdue principal and (to the
extent permitted by applicable law) on overdue installments of interest
(including without limitation during the 5-day period referred to in Section 4.1(b) of
the Indenture) shall accrue at the rate per annum set forth above.


 


The Series H Senior Notes are payable on
a parity basis with the Old Notes issued under the Indenture and the Fifth
Supplemental Indenture, dated as of April 1, 2008, in the aggregate
principal amount of $300,000,000.  The Series H
Senior Notes are being issued in exchange for a like principal amount of Old
Notes and the combined aggregate principal amount of the Series H Senior
Notes and the Old Notes outstanding at any one time is limited to
$300,000,000.  Pursuant to the Indenture,
the Old Notes and the Series H Senior Notes shall be treated as the same
series and the holders of the Old Notes and the Series H Senior Notes
shall vote and consent together on all matters as one class, and none of the
holders of the Old Notes or the Series H Senior Notes shall have the right
to vote or consent as a separate class on any matter.


 


Reference is made to the further provisions
set forth on the reverse hereof.  Such
further provisions shall for all purposes have the same effect as though fully
set forth at this place.


 

















 


This Senior Note shall not be entitled to any
benefit under the Indenture, or be valid or obligatory, until the certificate
of authentication hereon shall have been duly signed by the Trustee acting
under the Indenture.


 


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


 


	
   

  	
  AMEREN ENERGY GENERATING COMPANY

  
	
   

  	
   

  
	
   

  	
   

  
	
   

  	
  By:

  	
   

  
	
   

  	
   

  	
  Name:

  
	
   

  	
   

  	
  Title:

  
	
  (SEAL)

  	
   

  
	
  Attested:

  	
   

  
	
   

  	
   

  
	
   

  	
   

  
	
  By:

  	
   

  	
   

  
	
  Name:

  	
   

  
	
  Title:

  	
   

  
				



 

















 


[FORM OF REVERSE OF SERIES H SENIOR
NOTE]


 


AMEREN ENERGY GENERATING COMPANY


 


7.00% Senior Notes, Series H Due 2018


 


This Senior Note is one of a duly authorized
issue of debt securities of the Issuer, limited to the aggregate principal
amount of $300,000,000 (except as otherwise provided in the Indenture mentioned
below), issued or to be issued pursuant to an Indenture dated as of November 1,
2000 as supplemented by the Sixth Supplemental Indenture dated as of July 7,
2008 (as so supplemented, the “Indenture”), duly executed and delivered
by the Issuer to the Trustee.  Reference
is hereby made to the Indenture and all indentures supplemental thereto for a
description of the rights, limitations of rights, obligations, duties and
immunities thereunder of the Trustee, the Issuer and the Holders (the words “Holders”
or “Holder” meaning the registered holders or registered holder) of the Series H
Senior Notes.  Capitalized terms used
herein, but not otherwise defined herein, shall have the meanings assigned to
them in the Indenture.


 


In case an Event of Default shall have
occurred and be continuing, the principal of all the Securities may be declared
due and payable, in the manner and with the effect, and subject to the
conditions, provided in the Indenture. 
The Indenture provides that in certain events such declaration and its
consequences may be waived by the Holders of a majority in aggregate principal
amount of the Securities then Outstanding and that, prior to any such
declaration, such Holders may waive any past default under the Indenture and
its consequences except a default in the payment of principal of or premium, if
any, or interest on any of the Securities and as otherwise provided in the
Indenture.  Any such consent or waiver by
the Holder of this Senior Note (unless revoked as provided in the Indenture)
shall be conclusive and binding upon such Holder and upon all future Holders
and owners of this Senior Note and any Security which may be issued in exchange
or substitution hereof, whether or not any notation thereof is made upon this
Senior Note or such other Security.


 


The Indenture permits the Issuer and the
Trustee, with the consent of the Holders of not less than a majority in
aggregate principal amount of the Securities of all series at the time
Outstanding considered as one class, evidenced as in the Indenture provided, to
modify the Indenture or any supplemental indentures or the rights of the
Holders of the Series H Senior Notes; provided that no such
modification shall (a) change the Stated Maturity of the principal of, or
any installment of principal of or interest on, any Security, or reduce the
principal amount thereof, or reduce the rate or extend the time of payment of
interest thereon, or reduce any amount payable on redemption thereof or impair
or affect the right of any Holder of the Security to institute suit for the
payment thereof without the consent of the Holder of each Security so affected;
or (b)(i) reduce the aforesaid percentage of Securities, the consent of
the Holders of which is required for any such modification or the percentage of
Securities, the consent of Holders of which is required for any waiver provided
for in the Indenture; (ii) change any obligation of the Issuer to maintain
an office or agency for payment of and transfer and exchange of the Securities;
or (iii) make certain changes to provisions relating to waiver or to the
provision for supplementing the Indenture; in each case without the consent of
the Holders of all Securities then Outstanding.


 

















 


No reference herein to the Indenture and no
provision of this Senior Note or of the Indenture shall alter or impair the
obligation of the Issuer, which is absolute and unconditional, to pay the
principal of and premium, if any, and interest on this Senior Note at the
place, times, and rate, and in the currency, herein prescribed.


 


The Series H Senior Notes are issuable
only as registered Series H Senior Notes without coupons in denominations
of $100,000 and any integral multiple of $1,000 in excess thereof.


 


At the office or agency of the Issuer
referred to on the face hereof and in the manner and subject to the limitations
provided in the Indenture, Series H Senior Notes may be presented for
exchange for a like aggregate principal amount of Series H Senior Notes of
other authorized denominations.


 


Upon due presentment for registration of
transfer of this Senior Note at the above-mentioned office or agency of the Issuer,
a new Series H Senior Note or Series H Senior Notes of authorized
denominations, for a like aggregate principal amount, will be issued to the
transferee as provided in the Indenture. 
No service charge shall be made for any such transfer, but the Issuer
may require payment of a sum sufficient to cover any tax or other governmental
charge that may be imposed in relation thereto.


 


The Series H Senior Notes may be
redeemed in whole or in part (if in part, by lot or by such other method as the
Trustee shall deem fair or appropriate) prior to Stated Maturity at the option
of the Issuer, upon mailing a notice of such redemption not less than 30 nor
more than 60 days prior to the date fixed for redemption to the Holders of Series H
Senior Notes, all as provided in the Indenture, at a redemption price equal to
100% of the principal amount thereof plus accrued and unpaid interest thereon,
if any, to the date of redemption, plus the Applicable Premium.


 


Subject to payment by the Issuer of a sum
sufficient to pay the amount due on redemption, interest on this Senior Note
shall cease to accrue upon the date duly fixed for redemption of this Senior
Note.


 


The Issuer, the Trustee, and any authorized
agent of the Issuer or the Trustee, may deem and treat the registered Holder
hereof as the absolute owner of this Senior Note (whether or not this Senior
Note shall be overdue and notwithstanding any notation of ownership or other
writing hereon made by anyone other than the Issuer or the Trustee or any
authorized agent of the Issuer or the Trustee), for the purpose of receiving
payment of, or on account of, the principal hereof and premium, if any, and,
subject to the provisions on the face hereof, interest hereon and for all other
purposes, and neither the Issuer nor the Trustee nor any authorized agent of
the Issuer or the Trustee shall be affected by any notice to the contrary.


 


No recourse shall be had for the payment of
the principal of, or premium, if any, or the interest on this Senior Note, for
any claim based hereon, or otherwise in respect hereof, or based on or in
respect of the Indenture or any indenture supplemental thereto, against any
incorporator, shareholder, officer or director, as such, past, present or
future, of the Issuer or of any successor corporation, either directly or
through the Issuer or any successor corporation, whether by virtue of any
constitution, statute or rule of law or by the enforcement of any
assessment or penalty or 


 

















 


otherwise, all
such liability being, by the acceptance hereof and as part of the consideration
for the issue hereof, expressly waived and released.


 

















 


[FORM OF TRUSTEE’S CERTIFICATE OF
AUTHENTICATION]


 


Dated:


 


This is one of the Series H Senior Notes
referred to in the within-mentioned Indenture.


 


	
   

  	
  THE BANK OF NEW YORK MELLON

  TRUST COMPANY, N.A. (formerly known as

  THE BANK OF NEW YORK TRUST

  COMPANY, N.A.), as Trustee

  
	
   

  	
   

  
	
   

  	
   

  
	
   

  	
  By:

  	
   

  
	
   

  	
   

  	
  Authorized
  Signatory

  



 

















 


[FORM OF ASSIGNMENT]


 


I or we assign and transfer this Security to:


 


(Insert assignee’s social security or tax I.D.
number)


 


	
   

  	
   

  
	
   

  	
   

  
	
   

  	
   

  
	
   

  	
   

  
	
  (Print or
  type name, address and zip code of assignee)

  	
   

  
	
   

  	
   

  
	
  and
  irrevocably appoint:

  	
   

  
	
   

  	
   

  
	
   

  	
   

  
	
   

  	
   

  



 


Agent to transfer this Security
on the books of the Issuer.  The Agent
may substitute another to act for him.


 


	
  Date:

  	
   

  	
   

  	
  Your
  Signature:

  	
   

  	
   

  
	
   

  
	
   

  	
   

  	
   

  
	
   

  	
  (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 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.