Markit Economics released its final services purchasing managers' index (PMI) for the U.S. on Thursday. The final U.S. services PMI rose to 56.1 in August from 55.7 in July, 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 business.

"The US economy is enjoying a solid third quarter, with robust survey readings so far pointing to 2.5% annualised GDP growth. Employment growth is also holding up well, with PMI surveys signalling another month of non-farm payroll growth in excess of 200,000 in August," Markit Economics Chief Economist Chris Williamson noted.