U.S. markets stumbled early Tuesday with policy makers at the Federal Reserve headed into a two-day meeting in Washington.

The start of the Open Market Committee meeting often puts investors into a two-day holding pattern as they wait for critical news on the central bank's lending rate decisions.

Stocks retreated early, but railroad shares surged 11.58 percent after billionaire investor Warren Buffett said he would buy Burlington Northern Santa Fe for $44 billion.

In midmorning trading, the Dow Jones industrial average lost 0.18 percent, 17.76 points, to 9,771.68. The Standard & Poor's 500 index slipped 0.19 percent, 2.01, to 1,040.87. The Nasdaq composite index dropped 0.48 percent, 9.93, to 2,039.27.

The benchmark 10-year U.S. Treasury gained 4/32 to yield 3.409 percent.

The euro fell to $1.4658 from Monday's $1.4766. Against the yen, the dollar rose to 90.41 yen from Monday's 90.35 yen.

In Japan, the Nikkei 225 index lost 2.31 percent, 231.79, to 9,802.95.