Shell shutting Martinez, Calif. crude unit for a month -sources

HOUSTON, July 14 (Reuters) - Shell Oil Co was shutting the crude distillation unit at its 156,400 barrel per day (bpd) San Francisco Bay-area refinery in Martinez, California, on Tuesday for a month of planned work, according to sources familiar with refinery operations.

A Shell representative was not immediately available to discuss refinery operations.

Shell Oil is the U.S. unit of Royal Dutch Shell Plc (RDSa.L). (Reporting by Erwin Seba; editing by Carol Bishopric)