RANCE broker Marsh & McLennan is believed to be putting corporate investigations company Kroll up for sale.
Kroll declined to comment on the sale, but reports suggest it will be given a $1.3bn (£864m) price tag.
It is understood that Carlyle Group, Apax Partners and General Atlantic have all bid for the company, while BC Partners has also been named as a potential buyer.
Marsh & McLennan bought Kroll in 2004 for $1.9bn (£1.26bn).
Marsh & McLennan was not available for comment.