Stock index futures fell on Wednesday, a day after Wall Street jumped more than 2 percent, on new concerns about Spain's fiscal problems, while investors awaited data on producer prices and housing.

The premium that investors demand to hold 10-year Spanish government bonds rather than euro zone benchmark German Bunds, hit a euro lifetime high even as the European Commission denied a report the European Union, the International Monetary Fund and the U.S. Treasury were drawing up a liquidity plan for Spain. For details, see

The euro, used in the current climate to assess investors' risk appetite, briefly hit a two-week high before dropping against the U.S. dollar.

After the rumor about Spain and further problems that were denied, at least some people are questioning if a strong move (like Tuesday's) has to run out of steam a little bit, said Rick Meckler, president of investment firm LibertyView Capital Management in New York.

Further weighing on investor sentiment, FedEx Corp shares fell 2 percent premarket to $81.34 after the bellwether posted quarterly results.

S&P 500 futures fell 6.7 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 lost 52 points, and Nasdaq 100 futures dropped 7.25 points.

The S&P 500 closed above its 200-day simple moving average on Tuesday, and its ability to stay above that level could be tested.

The Commerce Department will release May housing starts and permits and the Labor Department reports the May producer price index, both at 8:30 a.m. EDT (1230 GMT). Economists expect housing starts at 650,000 and permits at 630,000, while monthly core PPI is seen at 0.1 percent.

The Federal Reserve releases May industrial production and capacity utilization data at 9:15 a.m. (1315 GMT), with capacity seen at 74.5 percent and monthly output expected up 0.9 percent.

Energy stocks will be in the spotlight as U.S. President Barack Obama, in a meeting with BP Plc executives later Wednesday, will demand it set aside billions of dollars to pay damages from the Gulf of Mexico oil spill.

Bank of America-Merrill has ordered traders not to enter into oil trades with BP that extend beyond June 2011, a source told Reuters.

BP's New York-traded stock lost 4.5 percent to $30 premarket.

Technical glitches thwarted AT&T Inc customers trying to reserve the latest version of Apple Inc's iPhone on Tuesday, the first day of preorders before the device hits stores on June 24.

U.S. shares surged on Tuesday as investors went on a buying spree, pushing the S&P 500 into positive territory for 2010.

(Reporting by Rodrigo Campos; editing by Jeffrey Benkoe)