UPDATE 1-U.S. May industrial production unchanged

(Adds details from report)

WASHINGTON, June 15 (Reuters) - U.S. industrial production was surprisingly flat in May as utilities and automotive production decreased, while capacity utilization was a slacker-than-expected 81.3 percent, a Federal Reserve report showed on Friday.

Analysts polled by Reuters were expecting industrial production to rise 0.2 percent and the nation's factories, mines and utilities to use capacity at an 81.6 percent rate.

Manufacturing output rose by 0.1 percent in the month, while mining production gained 0.5 percent. Utilities output fell by 1.3 percent because of unusually cold temperatures in the month, the Fed said.

Production of motor vehicles and parts decreased 0.5 percent.

Capacity use at factories edged lower to 79.9 percent and eased at utilities to 84.7 percent, but at mines it expanded to 90.5 percent.