Markit Economics released its final services purchasing managers' index (PMI) for the U.S. on Wednesday. The final U.S. services PMI rose to 55.7 in July from 54.8 in June, up from the preliminary reading of 55.2.

A reading over 50 indicates expansion in the sector.

The increase was driven by a faster pace in new work.

"Growth has clearly slowed compared to this time last year, and a further drop in service sector companies' optimism about the year ahead to one of the lowest seen over the past five years indicates that firms are expecting growth to slip further in coming months. Hiring could soon wane unless business confidence picks up again soon," Markit Economics Chief Economist Chris Williamson noted.