Wall Street stocks were set to drift lower at the open on Thursday as investors took a breather after the S&P 500 posted its best gains since August in a powerful rally.

Potentially curbing appetite for risk assets, weekly jobless claims rose unexpectedly last week, popping above 400,000 for the first time in a month and reinforcing the view the battered labor market was healing slowly.

Jobless claims are not falling. They're not in a danger zone, but the trend is not becoming healthier, said Pierre Ellis, senior economist at Decision Economics in New York.

S&P 500 futures dipped 2.7 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 32 points, while Nasdaq 100 futures lost 1 point.

Equities surged Wednesday after major central banks in a joint action agreed to make cheaper dollar loans for struggling European banks to prevent the euro zone debt crisis from worsening. The Dow posted its best day since March 2009, and both the Dow and S&P rose more than 4 percent.

In company news, Yahoo Inc shares were up 4.7 percent at $16.44 in premarket trade after Reuters reported Blackstone Group LP and Bain Capital along with Asian partners were preparing a bid in a deal valued at about $25 billion.

Shares of Kroger Co rose 2.9 percent to $23.18 in premarket trade after the largest U.S. supermarket chain raised its profit forecast.

China's factory sector shrank in November in the face of weakening demand both at home and abroad. The data may feed worries the global economy was sputtering.

The Institute for Supply Management releases its November manufacturing index at 10 a.m. EST. Economists expect a reading of 51.5 versus 50.8 in October.

The Commerce Department reports on October construction spending at 10 a.m. Economists forecast an increase of 0.3 percent, compared with a 0.2 percent rise in September.

The Federal Reserve releases weekly money stock, liquid assets and debt measures and the weekly report on factors affecting reserves of depository institutions and the condition statement of the Federal Reserve banks at 4:30 p.m. EST.

(Reporting by Angela Moon; editing by Jeffrey Benkoe)