Stock index futures pointed to a rise of about 2 percent at the open on Thursday after China denied a report it was reviewing its holdings in euro-zone sovereign bonds due to the region's debt crisis.

The People's Bank of China said a Financial Times report that Beijing was concerned about its euro-zone exposure was groundless. The FT report cut short a rally in the last session and pushed indexes into the red in a sign investors remained nervous after recent heavy losses.

In a familiar pattern seen in recent rebounds, financial and natural resource shares, among the worst hit during the selling, gained in premarket trade. Citigroup Inc rose 3.9 percent to $4.01, while United States Steel Corp added 3.6 percent to $46.73.

We have gone through a period of a very, very hard sell-off, and I think traders are looking for some evidence of a stopping point for those sales. This morning seems to be at least the first effort at a significant comeback, said Rick Meckler, president of investment firm LibertyView Capital Management in New York.

Also helping to sooth markets, Portugal said it was fully engaged in fiscal consolidation, while Spain's parliament passed a 15 billion euro ($18.4 billion) austerity package to cut its budget deficit.

St. Louis Federal Reserve President James Bullard said he did not expect contagion from Europe's fiscal problems to reach the United States, adding that the world's biggest economy may actually benefit from a flight to safety.

But LibertyView's Meckler said volatility would likely persist while Europe's problems remained unsolved. There's going to be a lot of emotional back-and-forth on the part of investors, he said. I would expect there will be days like this, and days with the same type of movement the other way.

S&P 500 futures jumped 24.1 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 soared 185 points, and Nasdaq 100 futures put on 41.75 points.

On the economic side, the second reading of first-quarter U.S. gross domestic product growth and weekly jobless claims will both be released at 8:30 a.m. EDT.

Economists forecast a 3.4 percent annualized rate of growth, and looked for new jobless claims to have fallen to 455,000 last week from 471,000 the week before.

In earnings news, H.J. Heinz Co posted higher quarterly profit, but also said annual earnings would be hit by currency fluctuations.

Warehouse club operator Costco Wholesale Corp and close-out retailer Big Lots Inc both recorded higher quarterly profit.

(Reporting by Edward Krudy; editing by Jeffrey Benkoe)