Industrial output increased by 0.8% last month – the biggest monthly gain since February – following a 0.9% fall in July.

Analysts had expected a rebound of just 0.2%.

By major industry groups, manufacturing output increased by 0.9% over the month, while mining output rose 0.8%, offsetting a stable performance by utilities production.

The Fed said that most of August's expansion came from the auto sector, with production of motor vehicles and parts surging 10.5%. If auto-related production is excluded, output would have risen by just 0.3%.