WASHINGTON (AP) — U.S. service companies, which employ nearly 90 percent of the work force, grew in September at the fastest pace since March, driven by more activity and an increase in new orders.

The Institute for Supply Management says its index of non-manufacturing activity rose to 55.1, up from 53.7 in August. Any reading above 50 indicates expansion.

The service sector has grown for 33 straight months, based on the ISM survey. The report measures growth in a broad range of businesses from retail and construction companies to health care and financial services firms.

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.