Exhibit 12.3

Central Illinois Public Service Company

Computation of Ratio of Earnings to Fixed Charges and Combined

Fixed Charges and Preferred Stock Dividend Requirements

(Thousands of Dollars, Except Ratios)

	Year Ended December 31,
	2005		2006		2007			2008			2009
Net income from continuing operations	$	42,998	$	37,372	$	16,535		$	14,739		$	28,897
Add- Taxes based on income		24,596		15,539		9,322			5,199			16,265
Net income before income taxes		67,594		52,911		25,857			19,938			45,162
Add- fixed charges:
Interest on short-term and long-term debt		28,969		29,932		36,670	(1)		29,422	(1)		28,315	(1)
Estimated interest cost within rental expense		—		726		899			760			1,216
Amortization of net debt premium, discount, and expenses		953		1,025		1,105			1,024			881
Total fixed charges		29,922		31,683		38,674			31,206			30,412
Earnings available for fixed charges		97,516		84,594		64,531			51,144			75,574
Ratio of earnings to fixed charges		3.25		2.67		1.66			1.63			2.48
Earnings required for combined fixed charges and preferred stock dividends:
Preferred stock dividends		2,512		2,512		2,512			2,512			2,512
Adjustment to pretax basis		1,437		1,045		1,416			886			1,414
		3,949		3,557		3,928			3,398			3,926
Combined fixed charges and preferred stock dividend requirements	$	33,871	$	35,240	$	42,602		$	34,604		$	34,338
Ratio of earnings to combined fixed charges and preferred stock dividend requirements		2.87		2.40		1.51			1.47			2.20

⁽¹⁾ Includes FIN 48 interest expense