WASHINGTON (Reuters) - U.S. private payrolls growth slowed sharply in February, the ADP National Employment Report showed on Wednesday.

Private payrolls increased by only 77,000 jobs last month after an upwardly revised 186,000 gain in January. Economists polled by Reuters had forecast private employment rising 140,000 following a previously reported 183,000 advance in January.

The ADP report, jointly developed with the Stanford Digital Economy Lab, was published ahead of Friday's more comprehensive and closely watched employment report for February from the Labor Department's Bureau of Labor Statistics. There is no correlation between the ADP and BLS employment report.

Private payrolls likely increased by 142,000 jobs in February, a Reuters survey showed, as the drag of unseasonably cold temperatures faded. Private employment rose 111,000 in January. Mass layoffs of federal workers, mostly on probation and with the United States Agency for International Development, are not expected to show in February's employment report as the purges happened outside the payrolls survey week.

Overall nonfarm payrolls are estimated to have increased by 160,000 jobs after rising 143,000 in January. The unemployment rate is forecast unchanged at 4.0%.