SEC FORM 4

SEC Form 4

FORM 4

UNITED STATES SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP

Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934
or Section 30(h) of the Investment Company Act of 1940

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Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).

1. Name and Address of Reporting Person^*

MUELLER CHARLES W

(Last)

(First)

(Middle)

P. O. BOX 66149, MC-1370

(Street)

ST. LOUIS

63166-6149

(City)

(State)

(Zip)

2. Issuer Name and Ticker or Trading Symbol
AMEREN CORP [ AEE ]

5. Relationship of Reporting Person(s) to Issuer
(Check all applicable)

X	Director	10% Owner
	Officer (give title below)	Other (specify below)

3. Date of Earliest Transaction (Month/Day/Year)
12/31/2003

4. If Amendment, Date of Original Filed (Month/Day/Year)

6. Individual or Joint/Group Filing (Check Applicable Line)

X	Form filed by One Reporting Person
	Form filed by More than One Reporting Person

Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned
1. Title of Security (Instr. 3)	2. Transaction Date (Month/Day/Year)	2A. Deemed Execution Date, if any (Month/Day/Year)	3. Transaction Code (Instr. 8)		4. Securities Acquired (A) or Disposed Of (D) (Instr. 3, 4 and 5)			5. Amount of Securities Beneficially Owned Following Reported Transaction(s) (Instr. 3 and 4)	6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	7. Nature of Indirect Beneficial Ownership (Instr. 4)
1. Title of Security (Instr. 3)	2. Transaction Date (Month/Day/Year)	2A. Deemed Execution Date, if any (Month/Day/Year)	Code	V	Amount	(A) or (D)	Price		6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	7. Nature of Indirect Beneficial Ownership (Instr. 4)
Common Stock, $.01 Par Value	07/01/2003		I	V	39⁽¹⁾	A	$41.98	1,408	I	By 401(k)
Common Stock, $.01 Par Value	09/30/2003		I	V	137⁽²⁾	A	$42.585	4,966	I	By ESOP
Common Stock, $.01 Par Value	01/02/2004	01/06/2004	J		1,000⁽³⁾	A	$46.357	1,000	D
Common Stock, $.01 Par Value	09/30/2003		L	V	173⁽⁴⁾	A	$42.585	11,796	D
Common Stock, $.01 Par Value	12/31/2003	01/05/2004	L		2,557⁽⁵⁾	A	$42.585	44,693⁽⁶⁾	D

Table II - Derivative Securities Acquired, Disposed of, or Beneficially Owned (e.g., puts, calls, warrants, options, convertible securities)
1. Title of Derivative Security (Instr. 3)	2. Conversion or Exercise Price of Derivative Security	3. Transaction Date (Month/Day/Year)	3A. Deemed Execution Date, if any (Month/Day/Year)	4. Transaction Code (Instr. 8)		5. Number of Derivative Securities Acquired (A) or Disposed of (D) (Instr. 3, 4 and 5)		6. Date Exercisable and Expiration Date (Month/Day/Year)		7. Title and Amount of Securities Underlying Derivative Security (Instr. 3 and 4)		8. Price of Derivative Security (Instr. 5)	9. Number of derivative Securities Beneficially Owned Following Reported Transaction(s) (Instr. 4)	10. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	11. Nature of Indirect Beneficial Ownership (Instr. 4)
1. Title of Derivative Security (Instr. 3)	2. Conversion or Exercise Price of Derivative Security	3. Transaction Date (Month/Day/Year)	3A. Deemed Execution Date, if any (Month/Day/Year)	Code	V	(A)	(D)	Date Exercisable	Expiration Date	Title	Amount or Number of Shares	8. Price of Derivative Security (Instr. 5)		10. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	11. Nature of Indirect Beneficial Ownership (Instr. 4)
Stock Option	$35.875							04/25/1997	04/25/2007	Common Stock, $.01 Par Value	15,000⁽⁷⁾		15,000	D
Stock Option	$43							02/27/1998	02/27/2006	Common Stock, $.01 Par Value	17,700⁽⁷⁾		32,700	D
Stock Option	$38.5							02/10/1999	02/10/2007	Common Stock, $.01 Par Value	23,300⁽⁷⁾		56,000	D
Stock Option	$39.25							04/28/2000	04/28/2008	Common Stock, $.01 Par Value	63,800⁽⁷⁾		119,800	D
Stock Option	$36.625							02/12/2001	02/12/2009	Common Stock, $.01 Par Value	75,300⁽⁷⁾		195,100	D
Stock Option	$31							02/11/2002	02/11/2010	Common Stock, $.01 Par Value	108,100⁽⁷⁾		303,200	D

Explanation of Responses:

1. Stock was acquired monthly from July through December 2003 at prices ranging from $41.98 to $45.975.

2. Stock was acquired during the third and fourth quarters of 2003 through reinvested dividends at $42.585 and $45.975, respectively.

3. Director Compensation

4. Stock was acquired during the third quarter of 2003 through reinvested dividends.

5. Represents 776 shares, 833 shares and 948 shares of stock acquired through reinvested dividends on restricted stock issued in 2001, 2002 and 2003, respectively. The dividends were paid during the third and fourth quarters of 2003 at $42.585 and $45.975 per share.

6. Restricted Stock

7. Shares vest annually in four equal installments starting on exercisable date.

Remarks:

	G. L. Waters, Asst. Secy. for Charles W. Mueller	01/07/2004
	** Signature of Reporting Person	Date
Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.
* If the form is filed by more than one reporting person, see Instruction 4 (b)(v).
** Intentional misstatements or omissions of facts constitute Federal Criminal Violations See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).
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