* China data disappoints
* Adobe up in premarket after results; to buy Fotolia
* PPI, UMich data on tap
* Futures off: Dow 85 pts, S&P 7.75 pts, Nasdaq 18 pts (Adds premarket actives)
By Chuck Mikolajczak
NEW YORK, Dec 12 (Reuters) - U.S. stock index futures fell on Friday, putting the benchmark S&P 500 on track to snap seven weeks of gains, after oil prices fell and Chinese data disappointed.
* The S&P index had snapped a three-day skid on Thursday, buoyed by upbeat retail sales figures and other data that pointed to a strengthening U.S. economy, but finished well off its session highs as oil prices slipped.
* Weak oil prices have added to worries about global demand and raised concerns about earnings for energy companies, with year-end tax selling putting more pressure on the group. The S&P energy sector has shed 14.7 percent this year and is the worst performing of the 10 major S&P sectors.
* Brent crude slipped to a low of $62.75, its lowest since July 2009, and was last down 0.6 percent at $63.30. WTI crude dropped below $60 a barrel and was last down 1 percent at $59.37 as worries persisted over a global supply glut and sluggish demand. The Select Sector Energy ETF was down 0.7 percent in premarket trade.
* Adding to pessimism was data indicating China's economy showed further signs of softening in November, as factory growth slowed more than expected and investment expansion hovered near a 13-year low.
* Economic data expected on Friday includes producer prices for November at 8:30 a.m. EST (1330 GMT) and the preliminary Thomson Reuters/University of Michigan's reading on consumer sentiment at 9:55 a.m. (1455 GMT). Analysts expect producer prices fell 0.1 percent from the prior month, and the data may influence the timing of the U.S. Federal Reserve's plan to raise interest rates next year. Consumer sentiment is forecast to show a reading of 89.5 for the month.
* Adobe Systems rose 7.5 percent to $75 in premarket after the company said it would buy stock photography company Fotolia for $800 million and reported quarterly revenue above market estimates.
* ChemoCentryx Inc surged 106 percent to $9.25 before the opening bell after the company said a combination of its experimental drug and the standard-of-care regimen was found to be superior in diabetics with progressive kidney disease than standard treatment alone. Volume of over 86,000 shares represented more than half its 10-day average.
Futures snapshot at 8:04 a.m. (1304 GMT):
* S&P 500 e-minis were down 7.75 points, or 0.38 percent, with 204,808 contracts changing hands.
* Nasdaq 100 e-minis were down 18 points, or 0.42 percent, in volume of 27,655 contracts.
* Dow e-minis were down 85 points, or 0.48 percent, with 12,810 contracts changing hands. (Editing by Bernadette Baum)