US STOCKS-Dow, S&P 500 end down slightly as Apple, energy weigh

* Fed meeting, more earnings reports awaited

* Apple (LSE: 0R2V.L - news) biggest drag on indexes

* Exxon, Chevron (Swiss: CVX.SW - news) fall as crude prices slip

* Pep Boys up after agreeing to be bought by Bridgestone (Other OTC: BRDCF - news)

* Dow down 0.1 pct, S&P down 0.2 pct, Nasdaq (NasdaqGS: NDAQ - news) up 0.1 pct (Updates to close)

By Caroline Valetkevitch

Oct (HKSE: 3366-OL.HK - news) 26 (Reuters) - The Dow and the S&P 500 edged lower on Monday as energy shares dropped with oil prices and Apple (Swiss: AAPL.SW - news) retreated a day before its quarterly results.

Investors were cautious ahead of the Federal Reserve's two-day policy meeting, which begins on Tuesday. The market is looking for clues on the outlook for when the Fed may begin raising interest rates.

Apple shares fell 3.2 percent to $115.28, making it the biggest drag on all three major indexes, while a weak outlook from one of its suppliers, Dialog Semiconductor (Xetra: 927200 - news) , led a fall in other semiconductors. An index of semiconductors was down 2 percent after three days of gains.

The iPhone maker reports quarterly results after the market closes on Tuesday.

"With Apple, it's more about their forecast and China news and any upgrades they may want to announce," said Rick Meckler, president of LibertyView Capital Management in Jersey City, New (KOSDAQ: 160550.KQ - news) Jersey.

The S&P energy sector fell 2.5 percent, leading sector declines for the S&P 500. Crude oil prices slipped as global oversupply pushed fuel storage sites close to capacity. Exxon fell 2.1 percent to $81.22, while Chevron was down 2.7 percent to $88.77.

U.S (Other OTC: UBGXF - news) . stocks have mostly gained in October after a weak third quarter. The S&P 500 is up 7.9 percent for the month so far.

"It (Other OTC: ITGL - news) 's been a pretty big move up, so we're seeing a little bit of consolidation today," Meckler said.

The Dow Jones industrial average fell 23.65 points, or 0.13 percent, to 17,623.05, the S&P 500 lost 3.97 points, or 0.19 percent, to 2,071.18 and the Nasdaq Composite added 2.84 points, or 0.06 percent, to 5,034.70.

Among the top Nasdaq gainers, hares of Ctrip.com was up 22.1 percent at $90.78 after the online travel firm said it would merge with Qunar Cayman Islands. Qunar jumped 7.9 percent to $42.65.

Strong quarterly results from tech companies have helped improve expectations for overall U.S. third-quarter earnings.

S&P 500 earnings are estimated to have declined a more modest 2.8 percent in the quarter, compared with 4.2 percent forecast at the start of the month, according to Thomson Reuters (Dusseldorf: TOC.DU - news) data.

Data showed new U.S. home sales fell 11.5 percent in September, suggesting a softening of the housing market. An index of housing shares was down 0.4 percent.

Among other gainers, Pep Boys jumped 23.4 percent to $14.99 after it agreed to be acquired by Bridgestone for $15 per share.

Piedmont Natural Gas rose 36.9 percent to $57.82 after it agreed to be bought by Duke Energy. Duke Energy fell 2.4 percent.

NYSE declining issues outnumbered advancers 1,916 to 1,153, for a 1.66-to-1 ratio; on the Nasdaq, 1,749 issues fell and 1,077 advanced, for a 1.62-to-1 ratio favoring decliners.

The S&P 500 posted 36 new 52-week highs and 8 lows; the Nasdaq recorded 111 new highs and 73 lows.

About 6.1 billion shares changed hands on U.S. exchanges, below the 7.3 billion daily average for the past 20 trading days, according to Thomson Reuters data. (Additional reporting by Abhiram Nandakumar in Bengaluru; Editing by James Dalgleish and Nick Zieminski)