Private employers added 55,000 jobs in May, compared with an upwardly revised gain of 65,000 in April, a report by a payrolls processor showed on Thursday.
The April figure was originally reported as a gain of 32,000.
The median of estimates from 31 economists surveyed by Reuters for the ADP Employer Services report, jointly developed with Macroeconomic Advisers LLC, was for a rise of 60,000 private-sector jobs in May.
The ADP figures come ahead of the government's much more comprehensive labor market report on Friday, which is expected to show a huge rise in nonfarm payrolls of 513,000 in May, based on a Reuters poll of analysts.
Economists often refer to the ADP report to fine-tune their expectations for the payrolls numbers, though it is not always accurate in predicting the outcome.