Wall St ticks up at open as Fed awaited

NEW YORK (Reuters) - U.S. stocks drifted slightly higher at the open on Wednesday with markets on tenterhooks ahead of the Federal Reserve's last policy announcement of the year, which might determine the immediate future of its 15-month long program to stimulate the economy.

The Dow Jones industrial average rose 36.99 points or 0.23 percent, to 15,912.25, the S&P 500 gained 1.77 points or 0.1 percent, to 1,782.77 and the Nasdaq Composite added 1.281 points or 0.03 percent, to 4,024.961.

(Reporting by Rodrigo Campos; Editing by Nick Zieminski)