Philadelphia-area refiners say they're shutting down production because the business is unprofitable; they say there are too many refiners serving a declining U.S. market for motor fuel even as they have to pay higher prices for imported crude. Sunoco Inc. has shut down its Marcus Hook refinery and says it will close its Philadelphia refinery by July 1 if it can't find a buyer. ConocoPhillips Co. shut its plant in Trainer last year.