Warren Buffett said his Berkshire Hathaway Inc was willing to invest $12.1 billion alongside 3G Capital in a deal for HJ Heinz Co because of his faith in the buyout firm led by Jorge Paulo Lemann.

"They are extraordinary managers," Buffett said on May 4 at Berkshire's annual meeting in Omaha, Nebraska, where the company is based. "We stretched a little because of that."

Berkshire and 3G reached a deal in February valued at about $23.3 billion to buy ketchup-maker Heinz, agreeing to pay 20 percent more than the closing price before the acquisition was announced. Berkshire gets an equity stake of about $4.1 billion, as well as warrants and $8 billion in preferred shares paying a 9 percent annual dividend.