(Reuters) - Warren Buffett's Berkshire Hathaway and private equity firm 3G Capital will buy ketchup and baby food maker H.J. Heinz Co for $23.2 billion in cash, a deal that combines 3G's ambitions in the food industry with Buffett's hunt for growth. Including debt assumption, Heinz valued the transaction, which it called the largest in its industry's history, at $28 billion. Berkshire and 3G will pay $72.50 per share, a 19 percent premium to the stock's previous all-time high.