Exhibit 10.1


AMENDMENT
NO. 2 TO EMPLOYMENT AGREEMENT


This Amendment No. 2
to Employment Agreement (this “Amendment”) attaches to and forms part of that
certain Employment Agreement, effective as of January 1, 2001, and amended
as of September 29, 2004 (the “Agreement”), between Aon Corporation (the “Company”)
and Michael D. O’Halleran (the “Executive”).


WHEREAS, the Company and
the Executive mutually desire to further amend this Agreement, as provided in
this Amendment;


NOW, THEREFORE, in
consideration of the premises and the mutual agreements contained herein, the
parties hereby agree as follows:


1.             The last sentence of Section 1, “Employment,” is
hereby deleted and replaced with the following:


“The term of employment of the Executive pursuant to
this Agreement (the “Employment Period”) shall commence effective as of
January 1, 2001 (the “Effective Date”) and shall end on January 1,
2013.”


2.             Subsection 3(a), “Base Salary,” is hereby deleted
in its entirety and replaced with the following:


“(a) Base Salary.  From April 1, 2006 through the end of
the Employment Period, the Company shall pay to the Executive a base salary at
a rate of $1,000,000 per annum (“Base Salary”), payable in accordance with the
Company’s executive payroll policy.  Such
Base Salary shall be subject to increase (but not decrease) at the discretion
of the Company’s Chief Executive Officer and the Board.”


3.             Subsection 3(b), “Annual Bonus,” is hereby deleted in
its entirety and replaced with the following:


“(b)         Annual Bonus.  For each calendar year of the Employment
Period beginning with 2006, the Executive shall be eligible to participate in
the Senior Officer Incentive Compensation Plan, as approved by Aon’s
stockholders in 2001 (the “Plan”) and as amended or replaced from time to time thereafter.  For each calendar year of the Employment
Period beginning with 2006, the Executive’s target annual bonus shall be 100%
of Base Salary and his maximum annual bonus shall be not less than 200% of Base
Salary.”


4.             The following paragraph shall be added at the end of
Subsection 3(c), “Stock Awards”:


“Notwithstanding the foregoing, beginning with
calendar year 2007 the Executive shall not be entitled to receive any
additional grants of the contractual awards described immediately above.  In lieu thereof, effective May 18, 2006, the
Organization and Compensation Committee of the Company’s Board of Directors
(the “Committee”) awarded the Executive 83,964 target performance share units 









 



subject to the terms and conditions set forth
herein.  The award provides the Executive
with the opportunity to earn performance share units based on the achievement
of specified pre-tax net income targets for the Global Reinsurance Segment for
the performance period beginning on the first day of the second quarter of 2006
and ending on December 31, 2008. 
Performance shall be measured on a cumulative basis during the
performance period such that, to the extent that any such targets are not
satisfied for any year, the Executive may make up such shortfall in subsequent
years during the performance period.  The
earned performance share units shall be settled and paid in fully vested shares
of common stock of the Company as soon as is practicable after the last day of
the performance period, but not later than March 31, 2009, or such earlier date
as is necessary to comply with Section 409A of the Internal Revenue Code of
1986, as amended. The unearned performance share units shall be forfeited at
such time.  Other than as set forth
herein, the terms and conditions of the Company’s “Leadership Performance
Program” (“LPP”), a sub-plan of the Aon Stock Incentive Plan as approved and
adopted by the Company’s stockholders in 2001, as in effect on the effective
date hereof, shall govern the earning and settlement of the Executive’s performance
share units, including in the event of the Executive’s termination of
employment prior to the last day of the performance period and in the event of
a change in control of the Company.


The Executive shall be
eligible to receive awards under the LPP or successor program(s) for future
performance periods in accordance with the terms and conditions generally
applicable to similarly-situated senior executives.


5.             The Agreement is amended by adding after the last
section thereof the following:


“18.         Indemnification.  The Company shall maintain, for the benefit of
the Executive, director and officer liability insurance in form at least as
comprehensive as, and in an amount that is at least equal to, that maintained
by the Company for any other officer or director.  In addition, the Executive shall be
indemnified by the Company against liability as an officer and director of the
Company and any subsidiary or affiliate of the Company to the maximum extent
permitted by applicable law.  The
Executive’s rights under this Section 18 shall continue so long as he may be
subject to such liability, whether or not this Agreement may have terminated
prior thereto.


19.           No Mitigation; No Offset.  In no event shall the Executive be obligated
to seek other employment or take any other action by way of mitigation of the
amounts payable to the Executive under any of the provisions of this Agreement
and such amounts shall not be reduced whether or not the Executive obtains
other employment.”


6.             This Amendment is effective as of May 18, 2006.









 



IN WITNESS WHEREOF, the
parties hereto have executed this Amendment No. 2 to the Employment
Agreement as of May    , 2006.


	
  AON CORPORATION

  	
   

  	
  EXECUTIVE:

  
	
   

  	
   

  	
   

  
	
   

  	
   

  	
   

  
	
  By:

  	
  /s/ Gregory C.
  Case

  	
   

  	
   

  	
  /s/ Michael D.
  O’Halleran

  
	
   

  	
   

  	
   

  	
   

  	
  Michael D.
  O’Halleran

  
	
  Title:

  	
  President and
  Chief Executive Officer