By Jarrett Renshaw

PHILADELPHIA (Reuters) - A brief fire that broke out at the Philadelphia Energy Solutions Inc refinery on Friday evening forced the closure of a core crude unit at the East Coast's biggest oil plant just ahead of the peak driving season.

The fire at the 335,000 barrel-per-day refinery occurred on a charge pump in the larger Girard Point half of the plant at around 5:40 p.m.(2140 GMT), the company said in a statement. It said no injuries had been reported and that the fire was out within an hour.

A source familiar with refinery operations told Reuters that the 200,000-bpd No. 137 sweet crude unit was shut down after the fire, while a second source said the refinery had not been completely shut down. Energy intelligence provider Genscape later reported that the crude unit as well as a related vacuum distillation unit at the refinery was shut.

It was unclear how much damage the fire caused or how quickly the unit might be running again. The Philadelphia plant, co-owned by the Carlyle Group and a unit of Energy Transfer Partners, is a major supplier of gasoline, diesel and jet fuel to the nation's biggest consuming area.

Oil markets were shut for the weekend before the fire was reported but fuel prices could jump next week if the disruption proves prolonged, particularly as gasoline demand is expected to be strong this summer due to lower prices.

(Reporting by Jarrett Renshaw in Philadelphia; Additional reporting by Sethuraman N R in Bengaluru; Editing by Leslie Adler)