Since co-founding Cerberus in 1992, Feinberg has homed in on companies so financially distressed - such as GMAC and ACE Aviation (Air Canada's parent) - that traditional leveraged-buyout investors shied away. He took that strategy to the hilt in May, when his firm bought 80% of Chrysler, the automaker that gave Daimler so much grief. The high-profile deal - and the high-wattage folks Feinberg has been recruiting to help run his acquisitions (e.g., Jim Press and Robert Nardelli at Chrysler) landed Cerberus near the top of the M&A heap.
Right now the portfolio includes more than 50 companies and about 250,000 employees. Combined, they ring up $120 billion in annual revenues, which would be enough to crack the Fortune 10 as a single conglomerate. --Katie Benner