U.S. industrial production fell more than expected in September, as a labor strike at a major car manufacturer reduced manufacturing output, according to a new report from the Federal Reserve.

Seasonally adjusted industrial production fell 0.4% month over month in September, following a revised increase of 0.8% in August. The consensus estimate from economists polled by Econoday was for a decline of 0.2% in industrial production.

Manufacturing output decreased 0.5% last month, when members of the United Auto Workers held a strike against General Motors Co. The labor action contributed to a drop of 0.7% for durable goods output.

The consensus estimate from economists polled by Econoday was for a 0.3% fall in manufacturing production in September.

The monthly declines in both industrial and manufacturing output were the biggest since April, data from the Fed showed.

Mining output fell 1.3% month over month in September, driven by declines in crude oil extraction and well drilling. Utilities output rose 1.4% amid higher demand for electricity due to warm weather.

Year over year, industrial production was down 0.1% in September.

Industrial capacity utilization fell 0.4 percentage point in September to 77.5%, a rate that is 2.3 percentage points lower than its long-run average.