U.S. factory activity unexpectedly shrank slightly in August while inflation pressures also eased, according to an industry report released Tuesday.

The Institute for Supply Management said its index of national factory activity edged lower to 49.9 in August from 50.0 in July, the level separating contraction from expansion.

Economists had expected an unchanged reading of 50.0, according to the median of their forecasts in a Reuters poll.

The 82 forecasts ranged from 47.8 to 52.0.