U.S. service firms grew more quickly last month as production, hiring and new orders increased, a sign that the economy is accelerating after dipping at the start of the year.

The Institute for Supply Management says its service-sector index rose to 56.3 in May from 55.2 in April. Any reading above 50 indicates expansion. The report points to solid growth after a brutal winter caused the economy to shrink 1% during the January-March quarter.

According to ISM, 17 non-manufacturing industries reported growth in May and only one (mining) reported contraction. "The majority of respondents' comments indicate that that there is steady incremental growth and project a positive outlook on business conditions," said the report.

The government issues its May jobs report on Friday. Employers added 288,000 jobs in April, and the unemployment rate fell to 6.3%. Economists expect 220,000 jobs were created in May, according to a FactSet survey.

But payroll processer ADP said Wednesday that private employers pulled back on hiring in May, adding just 179,000 jobs.

The Motley Fool recommends Automatic Data Processing. Try any of our Foolish newsletter services free for 30 days. We Fools may not all hold the same opinions, but we all believe that considering a diverse range of insights makes us better investors. The Motley Fool has a disclosure policy.