The Omaha, Nebraska-based investment and holding company's stock had its worst first half since 1990 and is down 18 percent this year through yesterday.
Buffett, 77, has been seeking acquisitions and funding takeovers while buyout firms struggle to borrow. Last month he pledged $3 billion to Dow Chemical Co.'s $15.4 billion buyout of Rohm & Haas Co. In April, Buffett agreed to put up $6.5 billion to help Mars Inc. buy Wm. Wrigley Jr. Co. in a deal that gives Berkshire a discounted stake in the chewing gum maker.
Berkshire had about $35 billion in cash as of March 31 and competing insurers including American International Group Inc. and MBIA Inc. have had to raise capital to cushion against losses from bad bets on the housing market. Buffett toured four European cities in May, drumming up potential acquisitions to boost earnings while U.S. insurance operations decline.