Exhibit 12.1

Aon Corporation and Consolidated Subsidiaries

Combined With Unconsolidated Subsidiaries

Computation of Ratio of Earnings to Fixed Charges

	Three Months Ended
	Mar. 31,					Years Ended December 31,
(millions except ratios)	2008		2007			2007			2006		2005		2004		2003
Income from continuing operations before provision for income taxes and minority interest	$	256	$	241		$	1,026		$	663	$	577	$	526	$	770
Less: Earnings from unconsolidated entities under the equity method of accounting	—		1			6			5		7		3		8
Add back fixed charges:
Interest on indebtedness (1)	33		35			138			129		125		136		101
Interest on FIN 48 liabilities	—		(1		)	(2		)	—		—		—		—
Portion of rents representative of interest factor	12		18			75			79		71		73		67
Income as adjusted	$	301	$	292		$	1,231		$	866	$	766	$	732	$	930
Fixed charges:
Interest on indebtedness (1)	$	33	$	35		$	138		$	129	$	125	$	136	$	101
Portion of rents representative of interest factor	12		18			75			79		71		73		67
Total fixed charges	$	45	$	53		$	213		$	208	$	196	$	209	$	168
Ratio of earnings to fixed charges	6.7		5.5			5.8			4.2		3.9		3.5		5.5

(1) As a result of the adoption of FIN 46 on December 31, 2003, Aon was required to deconsolidate its 8.205% mandatorily redeemable preferred capital securities. This decrease was offset by an increase in notes payable. Beginning in 2004, interest expense ($14 million for both the three months ended March 31, 2008 and 2007 and $58 million for the years ended December 31, 2007, 2006, 2005 and 2004) on these notes payable is reported as part of interest expense in the condensed consolidated statements of income.