* Automaker shares fall on worry about future sales
* Tesla's stock jumps after Morgan Stanley names it a top pick
* Amazon.com shares down, with holiday shopping in focus
* Yum Brands' November China sales flat, sending shares down
* Indexes down: Dow 0.7 pct, S&P 0.5 pct, Nasdaq 0.4 pct
NEW YORK, Dec 3 (Reuters) - U.S. stocks fell on Tuesday, sending the S&P 500 index lower for a third straight session as shares of retailers dipped after a disappointing start to holiday shopping and carmakers fell despite stronger-than-expected sales.
The market's drop was fed by a decline in the S&P consumer discretionary sector, which fell 1.1 percent. Shares of Ford Motor declined 3 percent to $16.54 while shares of General Motors were down 2.7 percent at $38.04 even as November auto sales for most companies exceeded expectations.
Some investors worry that pent-up demand would no longer support the current pace of sales gains after 2014, analysts said.
Among other consumer discretionary shares, Amazon.com Inc slipped 2 percent to $384.39 and was among the biggest drags on the S&P 500. The S&P retail index shed 1 percent after a disappointing to start to the holiday shopping season.
Earlier-than-usual online holiday discounts were expected to have dampened Cyber Monday sales in the United States. Still data firm comScore forecast U.S. online sales to have hit $2 billion on "Cyber Monday," the highest since the firm began tracking such information.
After eight weeks of gains in which the S&P 500 hit a series of record highs, investors may be locking in profits, analysts said. The S&P 500 is up 25 percent for the year so far.
"With the market being up so much in November, we're seeing some healthy profit-taking. It's been a very strong year in equtities," said Eric Marshall, director of research at Hodges Capital Management in Dallas, Texas.
Among the day's biggest gainers, Tesla Motors' stock jumped 14 percent to $141.63 with more than 18 million shares traded, well above its average levels, after Morgan Stanley named it a "top pick." Also, Germany's motor transport authority said on Monday it planned "no further measures" after reviewing fires in Tesla cars in the United States and Mexico .
The Dow Jones industrial average was down 117.23 points, or 0.73 percent, at 15,891.54. The Standard & Poor's 500 Index was down 8.98 points, or 0.50 percent, at 1,791.92. The Nasdaq Composite Index was down 15.88 points, or 0.39 percent, at 4,029.38.
"We've seen decent, but not great, spending at retailers at the start of the Christmas season," said Bryant Evans, portfolio manager at Cozad Asset Management in Champaign, Illinois, adding, "... online buying is flattening out the impact of the start of the season."
Investors speculated the Federal Reserve may move to trim its stimulus earlier than some had anticipated. Stronger-than-expected data on manufacturing and construction spending on Monday underscored views the Fed may begin scaling back its stimulus of $85 billion in monthly bond purchases sooner than expected.
Many analysts still forecast the announcement will take place in March, but investors will be closely watching this week's payroll jobs figures on Friday for clues to the Fed's thinking.
One of the biggest percentage decliners was Yum Brands Inc , which lost 2.6 percent to $75.68 after it said November sales at established KFC restaurants in China, its top market, failed to grow despite a successful promotion. It forecast a return to earnings per share growth in 2014.
Apple Inc acquired social media search and analytics company Topsy, which specializes in analyzing Twitter data. UBS upgraded the iPhone maker to "buy." Apple shares were up 1.7 percent to $560.35.