* Chinese factory activity contracts at fastest pace since 2012
* Fed vice-chair to speak at 1 p.m. ET
* Google, Mattel to report after the close
* Twitter jumps after rumors of private equity deal
* Indexes down: Dow 0.46 pct, S&P 0.48 pct, Nasdaq 0.25 pct (Adds details, changes quote, updates prices)
By Tanya Agrawal
Feb 1 (Reuters) - U.S. stocks pulled back on Monday as weak Chinese economic data exacerbated concerns about a global slowdown and oil prices resumed their slide.
The data from China showed that the world's second-largest economy's manufacturing sector contracted in January at the fastest pace since 2012.
Oil prices fell about 4 percent after the China data added to worries about demand and an OPEC source played down talk of an emergency meeting to stem the decline. Oil prices have fallen more than 70 percent since mid-2014.
Adding to the cautious note, data on Monday showed that U.S. consumer spending was unchanged in December and manufacturing activity continued to contract in January.
"The consumer spending numbers are a concern," said Randy Frederick, managing director of trading and derivatives for Charles Schwab in Austin, Texas.
"We keep hearing that there is pent-up consumer demand that we are going to see down the line but we've seen little evidence of that."
Consumer spending accounts for more than two-thirds of U.S. economic activity and is seen as a bright spot in an economy affected by weak export growth and efforts by businesses to reduce unsold merchandise.
The reports follow a weak reading of the GDP, which showed that the U.S. economy expanded at an anemic rate in the fourth quarter.
At 11:08 a.m. ET (1608 GMT) the Dow Jones industrial average was down 75.83 points, or 0.46 percent, at 16,390.47, the S&P 500 was down 9.23 points, or 0.48 percent, at 1,931.01 and the Nasdaq Composite index was down 11.52 points, or 0.25 percent, at 4,602.43.
Eight of the 10 major S&P sectors were lower, with the energy index's 2.6 percent fall leading the decliners. Oil majors Exxon and Chevron were down 2.5 percent and 1.9 percent.
Slammed by collapsing oil prices, stocks have had a volatile start to the year with traders expecting the Fed to scale back the number of rate hikes this year.
Coming off the worst January since 2009, the S&P 500 is already down 5 percent for the year. Traders are pricing in only a 17 percent chance that the Fed will raise rates in March.
Investors will pay close attention to Fed vice-chairman Stanley Fischer's speech on monetary policy at 1 p.m. ET.
Fourth-quarter corporate reporting season is well under way, with S&P 500 companies on average expected to post a 4.1 percent drop in earnings, according to Thomson Reuters I/B/E/S.
Internet giant Alphabet, which reports after the close, was up 0.5 percent at $765.48. Toy maker Mattel will also report after the close.
Alere jumped 45.2 percent to $54 after Abbott Laboratories agreed to buy the diagnostics company for $5.8 billion. Abbott was down 2.2 percent at $37.
Chipotle Mexican Grill was up 3.4 percent at $469 after the Wall Street Journal reported that an E. coli outbreak that affected the burrito chain's customers last year may be declared as over as soon as Monday.
Twitter was up 7.9 percent at $18.14 after rumors of a private equity deal.
Declining issues outnumbered advancing ones on the NYSE by 1,958 to 973. On the Nasdaq, 1,647 issues fell and 973 advanced.
The S&P 500 index showed 16 new 52-week highs and 4 new lows, while the Nasdaq recorded 16 new highs and 69 new lows. (Reporting by Tanya Agrawal; Additional reporting by Abhiram Nandakumar; Editing by Don Sebastian)