Aon Corp. (NYSE:AON) is giving more details about how it intends to handle the executives it expects to get when it closes on Hewitt Associates Inc. (NYSE:HEW)

Aon, Chicago, an insurance broker with a large consulting arm, announced plans in July to acquire Hewitt, Lincolnshire, Ill., a human resources consulting and benefits administration, for about $4.9 billion in cash and stock.

Aon said at the time that Hewitt Chairman Russell Fradin would become chairman of a new Aon Hewitt consulting unit and report to Aon Corp. Chief Executive Gregory Case.

Fradin now has a contract provision that requires an acquirer to pay him a substantial sum if it gets control over Hewitt. Fradin has agreed to a 5-year employee agreement that will covert much of the Hewitt “change in control” compensation into Aon restricted units that will be distributed only when he leaves Aon, Aon says.

Fradin also has agreed to keep any Aon stock he gets as compensation, minus any amounts sold to pay taxes and exercise prices, until he leaves Aon.

Aon says several top Hewitt executives – Kristi Savacool, Jim Knoieczny, David Baruch and Mark Sproat – will get top-level positions at Aon Hewitt.

Aon executives who will have top-level positions include Baljit Dail, Greg Besio, Scott Ordway and Neela Seenandan, Aon says.

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