US STOCKS-Futures decline on Fed taper timing concerns
* Apple up after Topsy buy, UBS upgrade
* Cyber Monday sales appear strong
* Yum Brands November China sales flat
* Futures up: Dow 63 pts, S&P 4.7 pts, Nasdaq 4 pts
NEW YORK, Dec 3 (Reuters) - U.S. stock index futures fell on Tuesday, indicating the S&P 500 may fall for a third consecutive day on concerns a reduction in stimulus by the Federal Reserve may be on the horizon earlier than some had anticipated.
The benchmark S&P index fell on Monday as stronger-than-expected data on manufacturing and construction spending prompted speculation the Fed may lean towards scaling back its stimulus of $85 billion in monthly bond purchases.
While virtually all market participants accept the central bank will begin to trim the stimulus at some point, the timing remains in question, with many analysts expecting the announcement in March.
"Very strong data would certainly set the stage for a January move to taper, but I'd be surprised to see them take any significant step in the waning weeks of the year," said Rick Meckler, president of investment firm LibertyView Capital Management in Jersey City, New Jersey.
"But the fact remains that it is coming, and they have given us so much time to prepare for it that it may well be not as significant an event when they finally do and maybe that has been their plan all along."
The Fed has said it would begin to slow the program when certain economic measures meet its targets. The economic calendar is packed this week with data that may provide some insight, culminating with the November payrolls report on Friday.
S&P 500 futures fell 4.7 points and were below fair value, a formula that evaluates pricing by taking into account interest rates, dividends and time to expiration on the contract. Dow Jones industrial average futures fell 63 points and Nasdaq 100 futures lost 4 points.
After a disappointing to start to the holiday shopping season, U.S. online sales are expected to hit $2 billion on "Cyber Monday," the highest since the data firm comScore began tracking such information. Amazon.com Inc shares slipped 0.8 percent to $389.36 in light premarket trade.
Apple Inc has acquired social media search and analytics startup Topsy, an unusual purchase for a hardware-focused company that has made few forays into social networking. The iPhone maker was subsequently upgraded to a "buy" rating by UBS. Apple shares were up 0.9 percent to $556.10 in premarket trade.
Yum Brands Inc lost 2.1 percent to $76.09 in premarket after it said said November sales at established KFC restaurants in China, its top market, failed to grow despite a successful half-priced chicken promotion, and it forecast a return to earnings per share growth in 2014.
European stocks dipped to near three-week lows, with miners tracking a fall in metals prices and Asian shares also fell as a batch of upbeat U.S. economic data on Monday suggested the Federal Reserve may tilt towards reducing its stimulus soon.