Private-equity managers from Fortress Investment Group LLC to Blackstone Group LP, which made billions by buying low and selling high, say now is the time to exit investments as stocks rally and interest rates start to rise.

Fortress, the first publicly traded buyout firm in the U.S., is preparing holdings for public offerings while struggling to find attractive new deals, Wesley Edens, who runs Fortress's $14.3 billion private-equity business, said on a conference call with investors yesterday. That environment extends to credit and distressed investments, said Pete Briger, who oversees the New York-based firm's $12.5 billion credit business.

"This is a better time for selling our existing investments than making new investments," Briger said on the call. "There's been more uncertainty that's been fed into the markets."