Private sector in the U.S. added 185,000 jobs in July, according the ADP report on Wednesday. June's figure was revised down to 229,000 jobs from a previous reading of 237,000 jobs.

Analysts expected the private sector to add 215,000 jobs.

"Job growth is strong, but it has moderated since the beginning of the year. Layoffs in the energy industry and weaker job gains in manufacturing are behind the slowdown. Nonetheless, even at this slower pace of growth, the labour market is fast approaching full employment," the Chief Economist of Moody's Analytics Mark Zandi said.

Official labour market data will be released on Friday. Analysts expect that U.S. unemployment rate is expected to remain unchanged at 5.3% in July. The U.S. economy is expected to add 218,000 jobs in July, after adding 223,000 jobs in June.