The National Association of Realtors is expected to report that pending sales of existing homes declined in March, according to economists surveyed by Thomson Financial/IFR. And ahead of that report, the Labor Department is anticipated to release its first-quarter reading on worker productivity and costs - one of many key gauges of inflation.

Inflation has become a prime concern on Wall Street, given that oil has doubled over the past year to record levels above $122 a barrel on Tuesday. As a result, gasoline prices are also climbing further into record terrain, strapping debt-laden U.S. consumers with another financial burden.

Kansas City Federal Reserve President Thomas Hoenig in a speech late Tuesday cited inflation as his main worry.

The stock market will be closely watching the energy market's reaction Wednesday to the government's weekly report on U.S. fuel inventories. In premarket electronic trading Wednesday on the New York Mercantile Exchange, light, sweet crude futures fell 23 cents to $121.61 a barrel after reaching $122.73 overnight.