Warburg's biggest solo deal in the U.S. was a $4 billion buyout of Bausch & Lomb.
2008 Rank: 5
2007 Rank: 8
Recent buyout fundraising: $16.2 billionThe oldest firm on the list, dating back to 1966, Warburg likes to control its own LBOs, so it wasn't a player in any of the $10 billion-plus club deals of the past few years. Instead it was busy in China, India, and Korea, where it invested in stakes often less than $100 million. Its biggest solo deal in the U.S. was a $4 billion buyout of contact-lens maker Bausch & Lomb.
Headwind issue: In December 2007, the firm--led by senior advisor and former Bank of America CEO David Coulter--sank $1 billion into struggling bond insurer MBIA. Since then, MBIA has lost two-thirds of its value.
Worth noting: Warburg co-president Chip Kaye is the chairman of the U.S.-India Business Council. Next month he will pass the job to a friend, Indian-born PepsiCo CEO Indra Nooyi.
Source: Rankings are based on a firm's most recently raised buyout fund(s). Fortune looked at data from Capital IQ, institutional investors, and the companies themselves to determine the size of the most recently raised buyout funds. For some firms that means a fund that was raised in 2007; for others it might be 2006. Whatever the date, the most recent fund was the one we counted. In the case of companies that raise multiple funds simultaneously as opposed to raising a single fund at a time, we chose to count only those private equity funds that were not raised in public markets and that were earmarked for buyouts (as opposed to investments in debt, venture capital, or other ventures).