Private-sector employment in the U.S. rose by 179,000 jobs from April to May, down from the three-month average of 198,000, according to Automatic Data Processing Inc.’s (NASD: ADP) national employment report released today. The number of jobs added in May is down from the 215,000 jobs added in April; however, May’s job growth is still higher than the same month last year.

“Job growth moderated in May,” said Mark Zandi, chief economist at Moody’s Analytics, which produces the report with ADP. “The slowing in growth was concentrated in professional/business services and companies with 50-999 employees. The job market has yet to break out from the pace of growth that has prevailed over the last three years.”

Bloomberg reports the 179,000 increase in employment was the smallest in four months and below the 210,000 median forecast of economists surveyed by Bloomberg.

According to ADP’s report, the service-providing sector added 150,000 jobs in May, down from 194,000 in April. The goods-producing sector added 29,000 jobs in May, up from 21,000 jobs gained in April.

Small firms added the most jobs in the month with 82,000, followed by medium-sized companies with 61,000. Large businesses added 37,000 jobs.

The report is derived from a sample of ADP data from 411,000 U.S. business clients representing nearly 24 million U.S. employees. The report’s methodology utilizes ADP payroll data, U.S. Bureau of Labor Statistics employment data, and the Philadelphia Federal Reserve Bank’s Aruoba-Diebold-Scotti Business Conditions Index.