April industrial output weaker than expected (by Greg Robb)

WASHINGTON (MarketWatch) - The output of the nation's factories, mines and utilities was weaker-than-expected in April as a parts shortage due the Japanese earthquake led to a drop in auto assemblies, the Federal Reserve said Tuesday. Industrial production was flat in April, well below the 0.3% increase expected by economists surveyed by MarketWatch. Adding to a sense of weakness in the report, industrial output in February and March was also revised lower. Factory activity alone fell 0.4% in April, which was the first decline after nine straight monthly gains. Total motor vehicle assemblies dropped to a 7.9 million unit annual rate in April from a 9.0 million rate in March. Excluding motor vehicles and parts, factory production rose 0.2% in April. Capacity utilization - a gauge of slack in the economy - slipped to 76.9% in April from 77.0% in March.