The National Association of Purchasing Management-Chicago business barometer rose to 61.5 from 57.2 in April. Economists had forecast the index at 56.0. It was the highest level since October. A reading above 50 indicates expansion in the sector.

The employment component of the index rose to 52.8 from 47.2 in April. Prices paid eased to 76.9 from 77.2 and new orders rose to 69.6 from 60.8.