US private sector job creation was weaker than expected in August for the second month running, a new report by payrolls processor ADP shows.
US employers created 91,000 new posts in August, below economist expectations for a rise of 100,000.
The payroll figures for July were also revised down, from 114,000 previously reported to 109,000, the ADP National Employment Report said.
The report, jointly authored by ADP and Macroeconomic Advisers, is published just two days before US government non-farm payrolls data.
The ADP report is also believed to paint a rosier picture of the labour market than the official figures, Macroeconomic Advisers chairman Joel Prakken told a conference call.
Prakken said the ADP report did not factor in job losses in the government sector or striking workers such as those at telecoms giant Verizon, both of which will be reflected in the government figures on Friday.
"It seems to me Friday's number from the BLS [Bureau of Labor Statistics] could be a good deal weaker than the number we're reporting today," Prakken said.
But High Frequency Economics chief US economist Ian Shepherdson said the underlying government data would still reassure.
"Allowing for tendency of the ADP number to undershoot the official measure of private payrolls, the August reading is consistent with the latter rising by about 130,000, but the Verizon strike will take up to 45,000 off that," he said.