U.S. factories expanded last month at the weakest pace in a year, with orders, hiring and production all growing more slowly.

The Institute for Supply Management, a trade group of purchasing managers, says its manufacturing index slipped to 52.9 in February from 53.5 in January. It was the fourth straight drop and the lowest reading since January 2014. Still, any reading above 50 signals expansion.

Measures of production and employment fell sharply, though they remained in expansionary territory. That suggests that factories are still adding jobs but at a slower pace than in January.

U.S. manufacturers have been held back in recent months by weak growth in China, Europe and Japan. That's been partly offset by strong consumer demand in the United States.