The Institute for Supply Management (ISM) said its index of national factory activity fell to 51.7 from 52.1 the month before. The reading was just above expectations of 51 from a Reuters poll of 77 economists.
A reading above 50 indicates expansion in the manufacturing sector and a reading below 50 indicates contraction.
The employment index rose to 54.5 from 53.7 a month earlier. Expectations called for a reading of 52.8.
The prices paid index fell to 47.9 from 53.2, compared to expectations of 53.0. It was the lowest reading since February 2016 and marked the third time in six months that the prices-paid measure has dropped into contraction.
New orders dropped to 50.0 from 52.7.