UPDATE 2-Valero has small fire at St. Charles refinery

(Adds additional regulator comment)

NEW YORK, June 9 (Reuters) - Valero Energy Corp (VLO.N: Quote, Profile, Research) said a small fire shut a vacuum, crude and coking unit at its 185,000-barrel-per-day refinery in St. Charles, Louisiana, early Tuesday morning.

"We don't expect it to be a lengthy outage," said Valero spokesman Bill Day.

State regulators said the fire began about 4 a.m. CDT (0900 GMT).

It was quickly extinguished, according to a spokesman for the St. Charles Parish Homeland Security and Emergency Preparedness Department.

There were no injuries reported due to the fire, the spokesman said. The fire was out about 30 minutes after being reported.

"The fire is still under investigation," said a spokesman for the Louisiana Department of Environmental Quality who said that only part of the refinery was not operable.

He said the investigation into the cause of the fire could could take between two and six months. (Reporting by Janet McGurty in New York and Erwin Seba in Houston)