The Chicago Business Barometer, also known as the Chicago PMI, fell to 56.4 in April from 62.9 in the prior month.
Economists had expected little change, with analysts polled by the Wall Street Journal forecasting a 62 reading.
The index is 14.4 points below it’s reading from April 2021.
The index is produced by the ISM-Chicago with MNI. It is released to subscribers three minutes before its release to the public at 9:45 am Eastern.
The Chicago PMI is the last of the regional manufacturing indices before the national ISM data for April is released on Monday.
In March, the ISM factory index slipped to 57.1, which is its lowest level since September 2020.