* World economy shows evidence of rebound
* Futures add to gains after U.S. jobless claims
* Abercrombie & Fitch shares tumble after results
* Futures up: Dow 52 pts, S&P 8 pts, Nasdaq 22 pts
NEW YORK, Aug 22 (Reuters) - U.S. stock index futures were set to rise at the open on Thursday after upbeat data from the world's top economies more than offset lingering uncertainty over the Federal Reserve's asset purchases stimulus program.
The Dow industrials fell Wednesday for a sixth straight day and the S&P 500 closed below its 50-day moving average for a fourth session after minutes from the Fed's July meeting gave few clues on when and by how much the U.S. central bank will start reducing its $85 billion a month in bond purchases.
Investors were encouraged, however, after business surveys showed U.S. manufacturing activity hit a five-month high in August, growth in the euro zone was better-than-expected and China's manufacturing sector rebounded, providing evidence that the world economy is on the mend.
With earnings season winding down, investors are paying more attention to overseas data, according to Joe Bell, senior equity analyst at Schaeffer's Investment Research in Cincinnati.
U.S. data showed the number of Americans filing new claims for unemployment benefits rose last week but held close to a six-year low and gave a positive signal for hiring during the month.
"We've also had a decent little pullback and buyers are coming in," he said. "We'll see if the premarket momentum is going to extend into the open."
Other data on Thursday's schedule includes July leading economic indicators at 10 a.m. (1400 GMT).
S&P 500 futures rose 8 points and were above 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 rose 52 points, and Nasdaq 100 futures added 22 points.
Shares of Hewlett-Packard dropped 7.7 percent in premarket trading a day after the company reported a decline in Enterprise Group revenue, the company's second-largest division and a critical component of Chief Execitove Meg Whitman's plan to transform the company.
Abercrombie & Fitch shares tumbled 19 percent before the market's open after the apparel retailer said quarterly comparable sales fell a larger-than-expected 10 percent.
Sears Holdings, which operates Sears department stores and the Kmart discount chain, reported a much bigger-than-expected quarterly loss and its shares fell 8.5 percent in premarket trading.
GameStop, the world's largest retailer of video game products, posted results that topped Wall Street estimates, and its shares jumped 9.2 percent.