Billionaire investor Warren Buffett unveiled Tuesday a 44-billion-dollar "huge bet" on the US economic future with a bid for the shares it does not already own in Burlington Northern Santa Fe railway.

Buffett's Berkshire Hathaway holding group said it would purchase the remaining 77.4 percent of Burlington Northern Santa Fe (BNSF) that it does not currently own for 100 dollars per share.

The cash-and-stock offer values all of BNSF at 44 billion dollars, including 10 billion dollars in debt.

"It's an all-in wager on the economic future of the United States. I love these bets," said Buffett, known in financial circles as the "Oracle of Omaha," for unparalleled investing acumen.

The takeover bid represents a 31 premium over BNSF's closing share price Monday.

"Our country's future prosperity depends on its having an efficient and well-maintained rail system," said Buffett, Berkshire Hathaway's chairman and chief executive, adding that the deal was the biggest ever for his storied investment fund.

"America must grow and prosper for railroads to do well," Buffett said, adding that "the investment in BNSF is a huge bet on that company... and the railroad industry."

Burlington Northern president, chairman and CEO Matthew Rose said the company was equally excited by the deal.

"We are thrilled to have the opportunity to become a part of the Berkshire Hathaway family," said Rose.

"We admire Warren's leadership philosophy supporting long-term investment that will allow BNSF to focus on future needs of our railroad, our customers and the US transportation infrastructure," Rose added.

"This transaction offers compelling value to our shareholders and is in the best interests of all of our constituents including our customers and employees."

The deal requires approval by holders of two-thirds of the railway's shares not already held by Berkshire Hathaway and Department of Justice review.

The transaction is expected to be completed in the first quarter of next year.