The G.M. strike, which began on Sept. 16, led to a 4.2% decline last month in the making of autos. The automaker reached a tentative 4-year deal this week with workers who took to the picket lines for a month, so automaking could rebound in November. Excluding autos, factory output slipped a more modest 0.1% in September.
Total industrial production, which includes mining and utilities as well as manufacturing, slipped 0.4% in September. Mining output fell 1.3% last month because of less crude oil being extracted and fewer wells being drilled. Production at utilities improved 1.4% as warm weather boosted demand for electricity.
There was a slight decline in capacity utilization in September, a sign that the industrial sector is far from running at full speed. The capacity utilization rate was 77.5% in September, down from 77.9% in August.