New York-based Apollo Management LP is the sixth-largest private equity firm in the world, according to a 2008 ranking by industry trade magazine Private Equity International. Its core business is in leveraged buyouts and investing in distressed securities. Other interests include Nasdaq-traded Apollo Investment Corp., a mezzanine fund for the middle market.

Despite the turmoil in financial markets, in 2008 its Apollo Investment Fund VII raised nearly $15 billion. But some of Apollo’s recent investments have taken big hits, including Linens 'n Things, the home-goods retailer, which was forced to liquidate after a bankruptcy filing, and Realology, the troubled parent of real estate brokers Coldwell Banker and Century 21.

Apollo's roots trace back to junk-bond giant Drexel Burnham, which long ago went bust. Apollo founder Leon Black was once the protégé of Drexel's Michael Milken and had been DB’s head of M&A before founding Apollo in 1990.