NEW YORK (Reuters) - A small fire in the substation of Dominion Resources Inc's 710-megawatt Chesapeake coal/oil-fired power plant in Virginia briefly knocked out power to about 35,000 customers early Wednesday, a company spokesman said.

The fire, which started about 6:30 a.m. EST, did not cause any injuries. Local fire fighters put it out about five minutes after arriving, Dominion spokesman Dan Genest told Reuters.

The plant's four coal units were operating at the time of the fire but shut automatically and remain off line. Genest said the fire was in the substation and the company did not expect any damage to the plant.

He could not say when the plant would return to service.

The company restored power to homes and businesses within about 45 minutes, Genest said.

(Reporting by Scott DiSavino; editing by Jim Marshall)