Crude inventories from the U.S. Energy Information Administration come at 10:30 a.m.
The price of Brent crude fell to trade just above $53 a barrel on Wednesday as U.S. crude stock levels are expected to have surged for the 10th straight week to a new record high. The price of U.S. crude fell $1.22 cents to $42.22 a barrel.
FedEx posted earnings that beat on revenue that was slightly below estimates. The company's full-year guidance was also slightly lower than expected, but its commentary was generally upbeat and analysts have pointed out that FedEx guidance tends to be on the conservative side.
General Mills reported adjusted quarterly profit of 70 cents per share, 3 cents above estimates, with revenue also beating Street consensus. The cereal maker and food producer said it expects to continue "strong growth" during the current quarter.
Williams-Sonoma, Guess and Cintas are all due to report after the bell.
In Europe, stocks were mixed as investors await the outcome of the Fed's meeting.
For U.K. investors, the annual U.K. Budget statement is due to be presented by the country's finance minister, George Osborne, and will be keenly watched as it comes ahead of May's general election.
In the software market:
Oracle—The business software maker reported in-line quarterly profit of an adjusted 68 cents per share, although revenue fell below Street estimates. Oracle also raised its quarterly dividend by 25 percent to 15 cents per share.
Adobe Systems—The software firm reported an adjusted quarterly profit of 44 cents per share, beating estimates by 5 cents, while revenue was slightly above forecasts. Adobe did see a less-than-expected increase in subscribers to its Adobe Cloud service, although that was still 28 percent above a year ago.
Read MoreEarly movers: FDX, GIS, ORCL, MSFT, HLF & more
Microsoft—A blog post by Microsoft EVP Terry Myerson said Windows 10 will be available to consumers "this summer."