HOUSTON, Sept 30 (Reuters) - West Coast refined productsdifferentials were steady on Friday in thin trading at the closeof the week. Meanwhile, Shell reported a unit shutdown on Sept.30 at its 156,400 barrel per day refinery in Martinez,California, according to a regulatory filing. * October CARBOB in Los Angeles was pegged 3cents lower at a 27-cent a gallon premium to the NYMEX RBOBfutures contract. * In San Francisco, October CARBOB differentials rose by 1 cent to a 20-cent a gallon premium tothe NYMEX RBOB futures contract. * October Los Angeles CARB diesel roseslightly to a 5.5-cent a gallon premium to the NYMEX heating oilcontract. * Prompt Los Angeles jet fuel was flat at a3-cent a gallon discount to the NYMEX heating oil contract. * The front-month NYMEX RBOB futures contract rose by 2.06cents to settle at $1.4874 a gallon. The prompt heating oilfutures contract rose by 1.77 cents to settle at $1.5279a gallon. (Reporting by Liz Hampton; Editing by Tom Brown)