The premium for Los Angeles ethanol-blended reformulated gasoline surged 11 cents on Friday after reports of flaring at Valero's Wilmington, California, refinery, traders said.

CARBOB sold in Los Angeles for 37 cents a gallon over NYMEX RBOB, traders said.

A Valero spokesman said the flaring was caused by a problem in the sulfur recovery unit but was having no material impact on production.