Berkshire Hathaway, the investment vehicle of billionaire investor Warren Buffett, making its largest ever acquisition deal, today said  that it plans to buy the 77.4 per cent it does not already own in Burlington Northern Santa Fe Corporation (BNSF) for $34 billion in cash and stock.

Fort Worth, Texas based BNSF, with 2008 revenue of $18 billion is the parent company of the BNSF Railway, which owns and manages one of the largest railroad systems in North America.

BNSF Railway with 6,700 trains, operates 32,000 miles of track hauling cargo including grain, coal and so-called intermodal containers and competes with Union Pacific.

Omaha, Nebraska-based Berkshire Hathaway said its board of directors have signed a definitive agreement to acquire BNSF for $100 per share in cash and stock the remaining 77.4 per cent of outstanding shares not currently owned to increase its holdings to 100 per cent for $44 billion, including $10 billion of outstanding BNSF debt, making it the largest acquisition in Berkshire Hathaway history.

BNSF will continue to operate from its Fort Worth, TX headquarters and will become a wholly owned subsidiary of Berkshire Hathaway.

''Our country's future prosperity depends on its having an efficient and well-maintained rail system,'' said Warren E. Buffett, Berkshire Hathaway chairman and chief executive officer. ''Conversely, America must grow and prosper for railroads to do well.

Berkshire's $34 billion investment in BNSF is a huge bet on that company, CEO Matt Rose and his team, and the railroad industry. ''Most important of all, however, it's an all-in wager on the economic future of the US,'' said Buffett. ''I love these bets.''

''We are thrilled to have the opportunity to become a part of the Berkshire Hathaway family,'' said Matthew Rose, Burlington Northern Santa Fe chairman, president and chief executive officer.

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