EX-23 4 a2202065zex-23.htm EX-23
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Exhibit 23


CONSENT OF INDEPENDENT REGISTERED PUBLIC ACCOUNTING FIRM

        We consent to the incorporation by reference in the following Registration Statements:

Registration Statement    
Form   Number   Purpose
 

S-8

    33-27984  

Pertaining to Aon's savings plan

 

S-8

   
33-42575
 

Pertaining to Aon's stock award plan and stock option plan

 

S-8

   
33-59037
 

Pertaining to Aon's stock award plan and stock option plan

 

S-3

   
333-50607
 

Pertaining to the registration of 369,000 shares of common stock

 

S-8

   
333-55773
 

Pertaining to Aon's stock award plan, stock option plan, and employee stock purchase plan

 

S-3

   
333-78723
 

Pertaining to the registration of debt securities, preferred stock and common stock

 

S-4

   
333-168320
 

Pertaining to the registration of 4,545,566 shares of common stock registered on Post Effective Amendment No. 1

 

S-4

   
333-57706
 

Pertaining to the registration of up to 3,852,184 shares of common stock

 

S-3

   
333-74364
 

Pertaining to the registration of debt securities, preferred stock, common stock, share purchase contracts, and share purchase units

 

S-3

   
333-100466
 

Pertaining to the registration as amended of 2,707,018 shares of common stock

 

S-8

   
333-103344
 

Pertaining to the registration of common stock

 

S-8

   
333-106584
 

Pertaining to Aon's deferred compensation plan

 

S-8

   
333-145928
 

Pertaining to the registration of common stock

 

S-8

   
333-145930
 

Pertaining to the registration of common stock underlying equity securities issued to Aon's president and chief executive officer

 

S-3

   
333-159841
 

Pertaining to the registration of debt securities, preferred stock, common stock, convertible securities, share purchase contracts, share purchase units and guarantees

of our reports dated February 25, 2011, with respect to the consolidated financial statements of Aon Corporation and the effectiveness of internal control over financial reporting of Aon Corporation, included in this Annual Report (Form 10-K) for the year ended December 31, 2010.

/s/ ERNST & YOUNG LLP

Chicago, Illinois
February 25, 2011




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CONSENT OF INDEPENDENT REGISTERED PUBLIC ACCOUNTING FIRM