US STOCKS-Wall St higher 30 minutes ahead of Fed decision
* Fed announcement expected at 2 p.m. ET (1900 GMT)
* Yellen speaks half an hour later
* Traders see a more than 80 pct chance of hike on Wednesday
* Indexes up: Dow 0.21 pct, S&P 0.36 pct, Nasdaq 0.24 pct (Changes comment, updates to early afternoon)
By Tanya Agrawal
Dec 16 (Reuters) - U.S. stocks trimmed gains but remained in positive territory in afternoon trading on Wednesday, half an hour ahead of a widely anticipated interest rate hike by the Federal Reserve.
An increase in the Fed's benchmark rate, from near zero, would be the first since June 29, 2006. Traders see an 81.4 percent chance of a rate hike, according to the CME Group's FedWatch tool.
The U.S. central bank is expected to raise rates by a token 25 basis points, when it announces the outcome of its policy meeting at 2 p.m. ET (1900 GMT). Fed Chair Janet Yellen will hold a news conference by at 2:30 p.m. ET.
The Fed is expected to move gradually on subsequent rate hikes after the initial liftoff, according to a Reuters poll. That will help soothe jittery markets, which have been roiled recently by a rout in crude oil prices and a fall in the Chinese yuan. Continuación...