Aon Plc

Aon plc is a British multinational corporation headquartered in London, United Kingdom, that provides risk management services, insurance and reinsurance brokerage, human capital and management consulting. Aon has approximately 600 offices worldwide, serving 120 countries with 61,000 employees.

In January 2012, Aon announced that headquarters would be moved from Chicago to London.

Aon is the largest reinsurance broker in the world. In 2011, Aon was ranked as the largest insurance broker in the world based on revenue. As of 2012, Aon is the principal sponsor of the Premier League team Manchester United.

Aon was created in 1982, when the Ryan Insurance Group (founded by Pat Ryan in the 1960s) merged with the Combined Insurance Company of America (founded by W. Clement Stone in 1919). In 1987, that company was renamed to Aon, a Gaelic word meaning oneness. Combined Insurance was sold to ACE Limited in April 2008.