Berkshire, with a stake of less than 5 percent, joins veteran Wall Street raiders Carl Icahn and Nelson Peltz as investors in the food giant, the Journal said, citing a person familiar with the purchase.
Buffett has a history of betting on companies that have strong brands and are comeback stories. His investment could mean a vote of confidence that management is on the right track with its plan to restructure the company, according to the report.
Neither Kraft nor Berkshire Hathaway immediately returned calls seeking comment.
Kraft shares closed at $34.84 Wednesday on the New York Stock Exchange.
Our Standards: The Thomson Reuters Trust Principles.