US STOCKS-Wall St slips on rate uncertainty, economic data

* Crude oil lower; energy shares slip

* Apple (LSE: 0R2V.L - news) , Twitter (Xetra: A1W6XZ - news) to report after the close

* Rite Aid surges on reports Walgreens in buyout talks

* Indexes down: Dow 0.3 pct, S&P 0.5 pct, Nasdaq (NasdaqGS: NDAQ - news) 0.3 pct (Updates to late afternoon)

By Caroline Valetkevitch

Oct (HKSE: 3366-OL.HK - news) 27 (Reuters) - U.S (Other OTC: UBGXF - news) . stocks slipped on Tuesday on uncertainty about the U.S. rate outlook and after a gauge of U.S. business investment plans fell for a second straight month.

Declines in crude oil weighed further on energy shares, and the S&P energy index, down 1.4 percent, led sector declines for the S&P 500.

Shares (Berlin: DI6.BE - news) of Apple were down 0.5 percent at $114.68 ahead of its results after the close. Investors will watch for the iPhone maker's China sales and its forecast for the crucial holiday quarter.

The Federal Reserve began its two-day policy meeting. While expectations of a rate hike this week are slim, investors are looking for clues on when the Fed will begin to raise interest rates.

Bruce Zaro, chief technical strategist at Bolton Global Asset Management in Boston said investors are worried about what the Fed will say in its statement.

"I think the Fed has created a lot of uncertainty... by not raising rates. As long as they stay put, it's going to create that uncertainty," he said.

Casting more doubts on whether the Fed will raise rates this year, data showed U.S. non-defense capital goods orders excluding aircraft, a closely watched proxy for business spending plans, slipped last month after a downwardly revised decline in August.

At 3:00 p.m. the Dow Jones industrial average fell 60.63 points, or 0.34 percent, to 17,562.42, the S&P 500 lost 9.53 points, or 0.46 percent, to 2,061.65 and the Nasdaq Composite dropped 16.45 points, or 0.33 percent, to 5,018.25.

Twitter, up 2.6 percent at $31.72, and Gilead Sciences, up 1.5 percent at $110.22, also are due to report after the bell.

Healthcare was the only S&P 500 sector in positive territory. The index was up 1.4 percent after better-than-expected earnings from pharmaceutical majors Pfizer and Merck (Other OTC: MKGAF - news) .

Rite Aid shares jumped 41.2 percent to $8.59 after sources said Walgreens Boots Alliance Inc (Xetra: W8A.DE - news) is nearing a deal to buy the company.

Among other gainers, shares of hotel operators rose after the Wall Street Journal reported at least three Chinese firms looking to bid for Starwood Hotels & Resorts Worldwide Inc (NYSE: HOT - news) . Starwood shares were up 9.2 percent at $74.88 while shares of Marriott International (NasdaqGS: MAR - news) were up 1.3 percent at $77.58. (Additional reporting by Abhiram Nandakumar in Bengaluru; Editing by Saumyadeb Chakrabarty and Nick Zieminski)