Sandton, Johannesburg, 9 December 2010 – Aon South Africa, a leading risk management, insurance brokerage, actuarial consulting organisation and subsidiary of Aon Corporation
(NYSE:AON), has announced its firm intention to ultimately acquire the entire
business of JSE Limited listed insurance broking and risk advisory services
provider, Glenrand M·I·B.

The offer of R2.00 per Glenrand M·I·B ordinary share plus a R24 million payable to the
BEE shareholders, places a value of approximately R523 million on the proposed
transaction. A further amount of 30 cents per share, or approximately R75 million, will be in
an Escrow account and these funds will be released pending and conditional as the final
outcome of a legal dispute dating back to 2006. Subject to the necessary approvals by the
Securities Regulation Panel, the shareholders of Glenrand M·I·B, the Competition
Commission, as well as various other regulatory approvals, the transaction will make Aon
South Africa a leading global risk broker in its sector of the financial services market in
South Africa as well as a leading global broker in Africa with offices in 32 cities and towns
throughout the African continent.

Anton Roux, Aon sub Saharan Africa Chief Executive Officer, said, “The proposed
acquisition will elevate Aon’s position in the local market and provide our clients with a
global network and top talent while offering additional economies of scale in certain of our
niche segments. Glenrand M·I·B’s strong presence in the South African market is a
natural complement to Aon’s established Africa footprint.”

“This acquisition brings together two premier organizations and reinforces Aon’s strong
commitment to the African continent. Combining the best talent between our two
organizations enhances our ability to deliver world class solutions to our clients,” added
Steve McGill, Chairman and Chief Executive Officer of Aon Risk Solutions.

Glenrand M·I·B will add around 15 000 corporate and commercial clients to Aon –
including many of the JSE’s blue-chip companies - as well as over 60 000 personal lines
clients. Glenrand M·I·B’s existing operations in sub Sahara Africa will strengthen Aon’s
network, which together span 14 countries (excluding correspondents) across the region.
The combined entity will also increase the number of offices nationally to 17.

If the acquisition is approved, Glenrand M·I·B’s clients will have immediate access to Aon’s
global network spanning more than 500 offices in 120 countries across all business lines,
including access to Aon’s global broking centres in London, Singapore and Bermuda and
its reinsurance markets via Aon Benfield, the world’s leading reinsurance intermediary.
Aon Hewitt will provide the full suite of human capital consulting and outsourcing services.

In terms of the Black Economic Empowerment structure of the new entity, Aon confirms
that it envisages that at least 25% of the new shareholding will lie with BEE shareholders.

Subject to the requisite approvals being obtained, detailed strategic and operational
planning will be implemented and management structures finalised.

Glenrand M·I·B shareholders are expected to vote on the acquisition in due course and
once all approvals are obtained, Glenrand M·I·B will delist from the JSE.

About Aon
Aon Corporation (NYSE:AON) is the leading global provider of risk management services,
insurance and reinsurance brokerage, and human resource consulting 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 http://www.aon.com for more information on Aon and
http://www.aon.com/unitedin2010 to learn about Aon's global partnership and shirt sponsorship with Manchester United. 

About Aon South Africa
Aon South Africa is a leading provider of risk management services, insurance and reinsurance brokerage, human capital and management consulting, and speciality insurance underwriting. The company employs more than 600 professionals in its 9 offices in South Africa. Aon employs over 1,100 people in 13 African countries excluding correspondents. Aon South Africa’s head office is based in Sandton, Johannesburg.

Safe Harbor Statement
This press release contains certain statements related to future results, or states our intentions, beliefs and expectations or predictions for the future which are forward-looking statements as that term is defined in the Private Securities Litigation Reform Act of 1995. These forward-looking statements are subject to certain risks and uncertainties that could cause actual results to differ materially from either historical or anticipated results depending on a variety of factors. Potential factors that could impact results include: general economic conditions in different countries in which we do business around the world, changes in global equity and fixed income markets that could affect the return on invested assets, fluctuations in exchange and interest rates that could influence revenue and expense, rating agency actions that could affect our ability to borrow funds, funding of our various pension plans, changes in the competitive environment, our ability to implement restructuring initiatives and other initiatives intended to yield cost savings, changes in commercial property and casualty markets and commercial premium rates that could impact revenues, changes
in revenues and earnings due to the elimination of contingent commissions, other uncertainties surrounding a new compensation model, the impact of investigations brought by state attorneys general, state insurance regulators, federal prosecutors, and federal regulators, the impact of class actions and individual lawsuits including client class actions, securities class actions, derivative actions, and ERISA class actions, the cost of resolution of other contingent liabilities and loss contingencies, and the difference in ultimate paid claims in our underwriting companies from actuarial estimates. Further information concerning the Company and its business, including factors that potentially could materially affect the Company’s financial results, is contained in the Company’s filings with the Securities and Exchange Commission.

Media Contact:
Cathy Jackson
011 463 6372 / 082 900 6477
cathy@findleypr.co.za