Jules Kroll is biding his time. Three decades after he brought detective agencies out of the back alley into the boardroom, almost single-handedly creating the corporate security industry, the founder of Kroll Inc is looking for another challenge.

He sold Kroll to insurance giant Marsh & McLennan for $1.9bn four years ago and retired in July when Marsh’s leadership turned down his offer to buy it back. Now he is on gardening leave, waiting out a year-long, non-compete agreement.