UPDATE: ISM is re-correcting the May manufacturing index. The correct figure now stands at 55.4, not 56.0 as previously corrected or 53.2 as originally reported.
U.S. manufacturing activity slowed last month and construction spending rose less than expected in April, which could temper hopes of a sharp pick-up in economic growth this quarter.
The Institute for Supply Management (ISM) on Monday said its index of national factory activity fell to 53.2 in May from April's reading of 54.9. A reading above 50 indicates expansion.
The slowdown reflected some cooling in new order growth, production and hiring.
"It looks softer across the board. All the components grew at a slower pace. I don't think this signifies a big concern but manufacturing won't be leading the economy," said Gus Faucher, senior economist at PNC Financial Services in Pittsburgh.