US STOCKS-Wall St drifts lower as earnings, crude weigh
* Crude oil lower; Exxon, Chevron slip
* Apple, Twitter to report after the close
* Alibaba rises after strong results
* Rite Aid surges on report Walgreens in buyout talks
* Indexes down: Dow 0.21 pct, S&P 0.37 pct, Nasdaq 0.18 pct (Updates to early afternoon)
By Abhiram Nandakumar
Oct 27 (Reuters) - Wall Street was lower on Tuesday after mixed earnings reports from major U.S. companies, weaker-than-expected data and further declines in crude oil prices.
Investors are also watching the Federal Reserve, which began its two-day policy meeting. While expectations of a rate hike this week are slim, traders will parse the Fed's statement on Wednesday for clues on the timing of a liftoff.
Corporate results remain in sharp focus as investors assess the reports for measures companies are taking to grow revenue and protect profit margins. Continuación...