U.S. service firms expanded at a slightly slower yet still healthy pace in March, an encouraging sign after multiple reports last week pointed to a slowing economy.

The Institute for Supply Management says that its services index slipped to 56.5 last month, from 56.9 in February. Any reading over 50 indicated expansion.

Sales fell last month and dragged down the overall index. But measures of hiring and orders rose, evidence that services firms may see solid growth in the coming months.

The ISM is a trade group of purchasing managers. Its survey of services firms covers businesses that employ 90 percent of the American workforce, including retail, construction, health care and financial services companies.