Ketchup maker H.J. Heinz Co. agreed to be purchased for $28 billion Thursday by a consortium including Warren Buffett's Berkshire Hathaway and private equity firm 3G Capital.

Heinz (HNZ) shareholders will receive $72.50 a share in cash, a 20% premium over Wednesday's closing price, which was already near Heinz's record high. It will keep Heinz's headquarters in Pittsburgh.

Shares of Heinz shot even higher, to $72.90 a share, in premarket trading on the news. Shares of Berkshire (BRKA) were not trading pre-market.

Berkshire has investments in a number of high-profile companies, including Deere & Co. (DE), IBM (IBM) and Procter & Gamble (PG). But it also owns a number of companies outright, including fast-food chain Dairy Queen, insurer GEICO and the railroad company Burlington Northern Santa Fe.