NEW YORK, Feb 9 (Reuters) - Cash CBOB gasoline and ultra-lowsulfur diesel (ULSD differentials to futures benchmarksstrengthened on Monday by 1.50 cents after a strike by U.S.refinery workers expanded to two more plants in the region,traders and brokers said.
Chicago CBOB gasoline had sellers asking 4.25 cents underthe benchmark March RBOB gasoline futures contract, 1.50cents stronger than where it was valued late on Friday. Sellersof ULSD were asking 7.50 cents under March heating oil,after it traded at 9.00 cents under on Friday.
The United Steelworkers union said a strike by U.S.refinery workers expanded on Sunday to BP Plc's Whiting,Indiana, refinery and the company's joint-venture refinery withHusky Energy in Toledo, Ohio. (Reporting by Robert Gibbons)