London-based Aon insurance brokerage announced that Mark Chessher, a finance executive at Zurich Financial Services, has been appointed chief financial officer for Aon Limited and Aon Risk Services (UK).

The firm said Mr. Chessher will join the company later in the year, subject to Financial Services Authority approval, and will sit on the Aon Limited board.

He replaces John Cullen, who earlier this year was promoted to the role of global CFO for Aon Risk Services.

Mr. Chessher is currently CFO for the North American large corporate customer division of Zurich Financial Services, based in New York.

Prior to this he was Zurich's U.K. finance director for two years. He also served five years in Zurich's U.S. personal lines operation based in Los Angeles. He has also worked for KPMG in London and in Sydney, Australia.

Peter Harmer, Aon Limited chief executive, said in a statement that Mr. Chessher has "a sound knowledge of the insurance industry, along with five years of experience of interacting with the FSA," and his skills will help the company's growth strategy.

Mr. Chessher is a chartered accountant and an associate of the Chartered Insurance Institute.