US STOCKS-Dow, S&P hit new highs on Fed; Twitter options debut

* NY factory index falls in Nov to weakest since May-NY Fed

* Twitter (NYSE: TWTR - news) options begin trading

* Exxon Mobil (TLO: XOM-U.TI - news) , J.C. Penney gain after hedge fund filings

* Indexes up: Dow 0.3 pct, S&P 0.2 pct, Nasdaq 0.1 pct

By Angela Moon

NEW YORK, Nov 15 (Reuters) - The Dow and the S&P 500 climbed to fresh highs on Friday in the wake of reassuring remarks by Federal Reserve chair nominee Janet Yellen that the central bank's accommodative policies would continue.

Still, the advance was limited, with both indexes on track for a sixth consecutive week of gains and the S&P 500 less than 10 points away from 1,800, its next level of potential resistance. The Nasdaq 100 index was near a 13-year high.

A divergence continued between large-cap and mid- and small-cap stocks - viewed to be riskier as they exhibit greater sensitivity to macroeconomic factors - with the Russell 2000 index of small- and mid-cap stocks flat at 1,111.37.

"Going forward, I'm keeping an eye on the 1,120 area on the Russell 2000, as small-cap leadership would be a good sign for risk appetite," said Bryan Sapp, senior trading analyst at Schaefer's Investment Research in Cincinnati, Ohio.

The Dow Jones industrial average was up 39.21 points, or 0.25 percent, at 15,915.43. The Standard & Poor's 500 Index was up 2.94 points, or 0.16 percent, at 1,793.56. The Nasdaq Composite Index was up 3.24 points, or 0.08 percent, at 3,975.98.

Exxon Mobil Corp rose 1.3 percent to $94.41 a day after Warren Buffett's Berkshire Hathaway Inc (NYSE: BRK-A - news) disclosed a new $3.45 billion stake in the world's largest publicly traded oil company.

J.C. Penney Co shares rose 3.3 percent to $8.98 after a number of hedge funds including Highfields Capital, Jana Partners (Other OTC: PGPHF - news) and Farallon Capital Management Group took positions in the ailing department store operator, and Glenview Capital, already a big owner, added to its holdings.

Following Twitter 's trading debut on the New York Stock Exchange on Nov. 7, options market makers began pricing and trading contracts Friday to buy or sell Twitter shares at various prices in the future.

Data showed New York state's manufacturing sector unexpectedly shrank this month while U.S. industrial production fell in October as output at power plants and mines declined. The market barely reacted to the reports.