Markit Economics released final services purchasing managers' index (PMI) for the U.S. on Wednesday. Final U.S. services purchasing managers' index (PMI) rose to 52.8 in April from 51.3 in March, up from the preliminary reading of 52.1.

A reading above 50 indicates expansion in the sector, a reading below 50 indicates contraction of activity.

The index was driven by a rise in new work and input prices, while job creation declined.

"The PMI surveys show the economy continuing to pick itself up after the stagnation seen in February, with growth accelerating for a second successive month in April," Chief Economist at Markit Chris Williamson said.

"However, the rate of expansion remains tepid, reliant on sluggish growth in services as manufacturers report a stalling of production," he added.