Stocks opened broadly lower, with blue chips headed for a third-straight loss, as weak data out of China set a negative tone while investors digested mixed corporate earnings.
The Dow Jones Industrial Average slid 134 points, or 0.8%, to 16239 shortly after the bell, putting the blue-chip barometer on track to suffer a third-straight decline.
The S&P 500 index gave up 13 points, or 0.7%, to 1832, and the Nasdaq Composite Index dropped 27 points, or 0.6%, to 4216.
On Wednesday, the Dow fell 41 points, or 0.3%, following downbeat earnings from some components, while the S&P 500 gained 0.1%.
Investor sentiment was being weighed down by data showing China's manufacturing activity contracted in January, raising worries that slowing momentum that the world's second-largest economy suffered at the end of 2013 may be carrying over into the new year.
Initial claims for jobless benefits inched up 1,000 to 326,000 in the latest week, compared with expectations of rise to 330,000.
