Aon Hewitt Best Employers in Canada Studies Focus on Increasing Employee Engagement

Canadian Organizations Invited to Participate as Annual Studies are Launched

TORONTO, March 9, 2011 � Aon Hewitt, the global human resource consulting and outsourcing business of Aon Corporation (NYSE:AON), announced today the official launch of the annual Best Employers in Canada studies. The data available to participating organizations enables them to not only measure their employees� engagement level, but to pinpoint exactly where they should concentrate efforts to increase employee engagement.

�High employee engagement is an important factor in business success,� stated Neil Crawford, a principal at Aon Hewitt and leader of the Best Employers in Canada study. �Our research shows that high employee engagement results in lower turnover, less absenteeism, greater employee productivity, and increased customer satisfaction. For many organizations, these benefits mean higher revenue growth and better economic returns.�

This year marks the launch of the 13th annual Best Employers in Canada study. The Best Small & Medium Employers in Canada study is sponsored by Queen�s School of Business and the Queen�s Centre for Business Venturing in conjunction with Aon Hewitt. Organizations that have operated in Canada for at least three years are eligible to participate in either the Best Small & Medium Employers study, for those with 50 to 399 employees, or the Best Employers study, for those with 400 or more employees. Participation is free and organizations have until the end of May to register at www.hewitt.com/bestemployerscanada.

Qualified participating organizations that have been most successful in building high employee engagement will be recognized on the annual list of the Best Employers in Canada this fall, to be published by Maclean�s magazine and La Presse newspaper. The Best Small & Medium Employers in Canada will be named in Profit magazine. Participants are also eligible for The Green 30, a list published in Maclean�s and Canadian Business that celebrates employers with eco-friendly practices. In addition, Greater Toronto Area organizations that take part in either study are considered for the Toronto Star�s Best Employers in the GTA list, which will also be published this fall.

�The Best Employers studies provide a roadmap for those organizations that understand high employee engagement is important and want to know where changes to their people practices will have the greatest impact on sustaining and improving engagement,� stated Crawford. �We invite all eligible organizations to take the first step to becoming a Best Employer by registering to take part.�

About Aon Hewitt

Aon Hewitt is the global leader in human capital consulting and outsourcing solutions. The company partners with organizations to solve their most complex benefits, talent and related financial challenges, and improve business performance. Aon Hewitt designs, implements, communicates and administers a wide range of human capital, retirement, investment management, health care, compensation and talent management strategies. With more than 29,000 professionals in 90 countries, Aon Hewitt makes the world a better place to work for clients and their employees. For more information on Aon Hewitt, please visit www.aonhewitt.com.

About Aon

Aon Corporation (NYSE:AON) is the leading global provider of risk management services, insurance and reinsurance brokerage, and human resources solutions and outsourcing. Through its more than 59,000 colleagues worldwide, Aon unites to deliver distinctive client value via innovative and effective risk management and workforce productivity solutions. Aon’s industry-leading global resources and technical expertise are delivered locally in over 120 countries. Named the world’s best broker by Euromoney magazine’s 2008, 2009 and 2010 Insurance Survey, Aon also ranked highest on Business Insurance’s listing of the world’s insurance brokers based on commercial retail, wholesale, reinsurance and personal lines brokerage revenues in 2008 and 2009. A.M. Best deemed Aon the number one insurance broker based on revenues in 2007, 2008 and 2009, and Aon was voted best insurance intermediary 2007-2010, best reinsurance intermediary 2006-2010, best captives manager 2009-2010, and best employee benefits consulting firm 2007-2009 by the readers of Business Insurance. Visit www.aon.com for more information on Aon and www.aon.com/manchesterunited to learn about Aon’s global partnership and shirt sponsorship with Manchester United.