WASHINGTON, Sept 17 Reuters Production at U.S. factories surged in August amid a rebound in motor vehicle output, but data for the prior month was revised lower, suggesting that manufacturing continued to tread water.

Factory output increased 0.9 last month after a downwardly revised 0.7 drop in July, the Federal Reserve said on Tuesday. Economists polled by Reuters had forecast factory output would rise 0.3 after a previously reported 0.3 decline in July.

Production at factories rose 0.2 on a yearonyear basis in August. Manufacturing, which accounts for 10.3 of the economy, continues to be hamstrung by higher borrowing costs. Relief could be on the way, with the U.S. central bank expected to start its policy easing cycle on Wednesday.

Motor vehicle and parts output accelerated 9.8 last month after dropping 8.9 in July. Durable manufacturing production increased 2.1 after decreasing 1.5 in July.

In addition to motor vehicles, there were gains in the output of primary metals, electrical equipment, appliances and components as well as aerospace and miscellaneous transportation equipment. But production of miscellaneous durable manufacturing goods fell 0.9.

Nondurable manufacturing production slipped 0.2, pulled down by printing and support, and petroleum and coal products, which offset gains in the output of chemicals and paper.

Mining output rebounded 0.8 last month after falling 0.4 in July. Early shutdowns in the petrochemical and related industries ahead of…