WASHINGTON (Reuters) - Production at U.S. factories unexpectedly fell in April amid a decline in motor vehicle output, data showed on Thursday.

Manufacturing output dropped 0.3% last month following a downwardly revised 0.2% increase in March, the Federal Reserve said. Economists polled by Reuters had forecast factory output rising 0.1% after a previously reported 0.5% advance in March.

Production at factories fell 0.5% year-on-year in April. Manufacturing, which accounts for 10.4% of the economy, remains constrained by higher borrowing costs.

A survey from the Institute for Supply Management early this month showed manufacturing regressing in April after growing in March for the first time in 1-1/2 years.

Motor vehicle and parts output decreased 2.0% last month after increasing 2.8% in March. Durable goods manufacturing production declined 0.5%. There were also decreases in the production of electrical equipment, appliances and components as well as wood products. But production of primary metals, computer and electronic products, aerospace and miscellaneous transportation equipment increased.

Production of nondurable goods dipped 0.1% as a 4.4% tumble in petroleum and coal products offset gains elsewhere.

Mining output fell 0.6% after dropping 1.1% in March. Utilities production increased 2.8% after rising 1.6% in the prior month. Overall industrial production was unchanged in April. That followed a 0.1% gain in March. Industrial production fell 0.4% year-on-year in April.

Capacity utilization for the industrial sector, a measure of how fully firms are using their resources, fell to 78.4% from 78.5% in March. It is 1.2 percentage points below its 1972-2023 average. The operating rate for the manufacturing sector slipped 0.3 percentage point in to 76.9% in April. It is 1.3 percentage points below its long-run average.

(Reporting by Lucia Mutikani; Editing by Andrea Ricci)