U.S. stock index futures point to a slightly lower open Thursday ahead of the publication of weekly jobless claims data and the first quarter's GDP number. 

Futures on the Dow Jones Industrial Average were up 0.02 percent while futures on the Standard & Poor's 500 Index were down 0.16 percent and those on the Nasdaq 100 Index were down 0.08 percent.

On Thursday, the Commerce Department will release GDP data for the world’s largest economy, which according to the most recent estimate is expected to clock in at 2.5 percent for the January-March quarter. The median forecast from a Bloomberg survey of economists agreed with this estimate.

Investors will also be looking to the weekly U.S. jobless claims report, which measures the number of individuals who filed for unemployment insurance for the first time last week, due to be released before the opening bell. Economists polled by Reuters predict that claims will remain unchanged at 340,000 levels for the week ending May 25 compared to the prior week.

In addition, the National Association of Realtors' pending home sales report, which measures the change in the number of homes under contract to be sold but still awaiting the closing transaction, excluding new construction, will be reported at 10:00 a.m. EDT on Thursday. It is expected that the report will show a 1.1 percent rise in April after gaining 1.5 percent in the previous month.

European stocks advanced slightly in early trading on Thursday. London’s FTSE 100 was up 0.24 percent, Germany's DAX-30 gained 0.01 percent and France's CAC-40 advanced 0.21 percent. Earlier, data from the euro zone showed that while consumer confidence was still in the red, there was a slight improvement to -21.9 from -22.3 in April. The European Commission's monthly survey also found that economic sentiment ticked up to 89.4 in May from 88.6 in April.

Earlier, Asian stock markets declined led by Japan's Nikkei, which fell more than 5 percent on heavy selling. The Nikkei plunged 5.15 percent or 737.43 points to 13,589.03 as exporters' stocks took a beating on currency fluctuations. The dollar declined closer toward the 100-yen level as investor sentiment was weighed down by concerns that the U.S. Federal Reserve could scale back its monthly bond-buying program in the next few months. 

“Speculation about the Fed may be affecting markets in Asia which have been rallying on funds flowing in as a result of the Fed's stimulus," Hirokazu Yuihama, a senior strategist at Daiwa Securities in Tokyo, told Reuters.

"But such speculation about the Fed scaling down its stimulus has been surfacing since the start of the year, and investors may eventually shift their focus to the region's moderate growth which will likely improve corporate earnings prospects, after the current adjustment phase is over," he said.

China’s Shanghai Composite declined 0.27 percent and South Korea’s KOSPI Composite fell 0.05 percent while Hong Kong’s Hang Seng declined 0.31 percent and India’s BSE Sensex slipped 0.31 percent.