Segment Information (Tables)

6 Months Ended

Jun. 30, 2012

Schedule Of Segment Reporting Information By Segment

Three Months	Ameren Missouri		Ameren Illinois		Merchant Generation			Other			Intersegment Eliminations			Consolidated
2012:
External revenues	$	838	$	561	$	261		$	-		$	-		$	1,660
Intersegment revenues		6		3		72			2			(83	)		-
Net income (loss) attributable to Ameren Corporation(a)		143		32		(5	)		41			-			211
2011:
External revenues	$	814	$	619	$	347		$	1		$	-		$	1,781
Intersegment revenues		8		4		49			-			(61	)		-
Net income (loss) attributable to Ameren Corporation(a)		90		37		15			(4	)		-			138
Six Months
2012:
External revenues	$	1,524	$	1,282	$	510		$	2		$	-		$	3,318
Intersegment revenues		11		6		159			2			(178	)		-
Net income (loss) attributable to Ameren Corporation(a)		164		59		(368	)		(47	)		-			(192	)
2011:
External revenues	$	1,581	$	1,424	$	679		$	1		$	-		$	3,685
Intersegment revenues		13		7		96			1			(117	)		-
Net income (loss) attributable to Ameren Corporation(a)		111		70		35			(7	)		-			209
As of June 30, 2012:
Total assets	$	12,680	$	7,127	$	3,254		$	1,196		$	(1,277	)	$	22,980
As of December 31, 2011:
Total assets	$	12,757	$	7,213	$	3,833		$	1,211		$	(1,369	)	$	23,645

(a) Represents net income (loss) available to common stockholders.