Exhibit 12.3

Ameren Illinois 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,
	2006		2007			2008			2009			2010
Net income from continuing operations attributable to Ameren Illinois Company	$	124,334	$	56,011		$	40,713		$	133,360		$	212,547
Add - Taxes based on income		66,504		26,571			15,866			78,970			136,614
Net income before income taxes		190,838		82,582			56,579			212,330			349,161
Add - fixed charges:
Interest on short-term and long-term debt		94,143		131,826	(a)		140,289	(a)		163,831	(a)		152,667	(a)
Estimated interest cost within rental expense		1,220		1,476			1,890			3,797			3,899
Amortization of net debt premium, discount, and expenses		5,269		10,624			11,058			6,317			5,250
Total fixed charges		100,632		143,926			153,237			173,945			161,816
Earnings available for fixed charges		291,470		226,508			209,816			386,275			510,977
Ratio of earnings to fixed charges		2.89		1.57			1.36			2.22			3.15
Earnings required for combined fixed charges and preferred stock dividends:
Preferred stock dividends		6,732		6,656			6,160			5,678			4,435
Adjustment to pretax basis		3,601		3,158			2,401			3,362			2,396
		10,333		9,814			8,561			9,040			6,831
Combined fixed charges and preferred stock dividend requirements	$	110,965	$	153,740		$	161,798		$	182,985		$	168,647
Ratio of earnings to combined fixed charges and preferred stock dividend requirements		2.62		1.47			1.29			2.11			3.02

^(a) Includes interest expense related to uncertain tax positions