Exhibit 12.1

Aon Corporation and Consolidated Subsidiaries

Combined With Unconsolidated Subsidiaries

Computation of Ratio of Earnings to Fixed Charges

	Three Months Ended
	March 31,				Years Ended December 31,
(millions except ratios)	2010		2009		2009		2008		2007		2006		2005
Income from continuing operations before provision for income taxes and noncontrolling interests	$	247	$	343	$	949	$	879	$	1,023	$	738	$	567
Less: Earnings from unconsolidated entities under the equity method of accounting	4		—		11		5		6		5		7
Add back fixed charges:
Interest on indebtedness	34		29		122		126		138		129		125
Interest on uncertain tax positions	—		—		2		—		2		—		—
Portion of rents representative of interest factor	11		9		48		47		75		79		71
Income as adjusted	$	288	$	381	$	1,110	$	1,047	$	1,232	$	941	$	756
Fixed charges:
Interest on indebtedness	$	34	$	29	$	122	$	126	$	138	$	129	$	125
Interest on uncertain tax positions	—		—		2		—		2		—		—
Portion of rents representative of interest factor	11		9		48		47		75		79		71
Total fixed charges	$	45	$	38	$	172	$	173	$	215	$	208	$	196
Ratio of earnings to fixed charges	6.4		10.0		6.5		6.1		5.7		4.5		3.9