NEW YORK (Reuters) - Shares of U.S. rail companies rallied in premarket trading on Tuesday, after Berkshire Hathaway (BRKa.N) agreed to buy Burlington Northern Santa Fe (BNI.N) for $100 per share in cash and stock.

Burlington shares surged 28 percent to $97. Among the company's peers, Union Pacific (UNP.N) gained 8.1 percent to $59.50, CSX Corp (CSX.N) was up 8.5 percent to $46.50 and the iShares Dow Jones Transportation Average ETF (ITY.P) climbed 1.4 percent to $65.15.

(Reporting by Ryan Vlastelica. Editing by W Simon )