Warren Buffett buying Burlington Northern

Los Angeles-based money manager Capital Group Cos, which oversees the $780 billion American Funds family of mutual funds, is likely one of the big winners in the deal.

The firm's fund unit held 23.2 million BNSF shares, or a 7 percent stake, as of June 30, according to data collected by Thomson Reuters. The firm was the largest shareholder after Buffett.

BETTING ON THE FUTURE OF COAL

Jack Ablin, chief investment officer at Harris Private Bank in Chicago, said the deal was a bet on the future of coal as a source of energy.

"Because Burlington Northern moves coal around the country, I think Buffett is trying to get into coal but doing it in a cheaper way," he said. "It's leveraged against coal's demand without actually having to buy the commodity itself."

Some analysts said the deal did not necessarily signal a wave of mergers and acquisitions in railroads.

"For an outsider to make an acquisition of a railroad or invest a significant amount in a railroad -- you may see more people get interested in that possibility," said George Van Horn, senior analyst with market research firm IBISWorld.

"But as far as seeing railroad themselves merging, I wouldn't expect that right away," he said.

Berkshire said the 50-for-1 split of its Class B shares, which is subject to shareholder approval, would make it easier for smaller BNSF shareholders to swap their stock for Berkshire stock. Class B shares were up 1.5 percent to $3,313.50 in early trading.

Buffett, one of the world's richest men and and one of its most revered investors, is known for making big long-term bets. He wrote in The New York Times in October 2008 that he had been buying American stocks in his personal account, a few weeks after the collapse of Lehman Brothers set off worldwide selling.