HOUSTON, May 9 (Reuters) - Gasoline retreated in the Los Angeles and San Francisco Bay spot markets on Thursday as traders said Royal Dutch Shell Plc (LSE: RDSB.L - news) was restarting a coking unit at its 156,400 barrel per day (bpd) Martinez, California, refinery.
May-delivery CARBOB fell 9 cents a gallon in L.A. to 36 cents a gallon over June NYMEX RBOB gasoline. In the Bay, May CARBOB slid 7 cents a gallon to 30 cents a gallon over June RBOB.
A Shell spokeswoman declined to discuss operations at the Martinez refinery on Thursday.
Gasoline in the Portland, Oregon, market remained at 55 cents a gallon over June NYMEX RBOB as Tesoro Corp works to restore production on the gasoline-producing fluidic catalytic cracking unit at its 120,000 bpd Anacortes, Washington, refinery.
A Tesoro spokeswoman said on Thursday that unplanned maintenance was being done on a unit at the refinery. She declined to identify the unit.
May CARB diesel rose 1.75 cents to a discount of 1 cent under June NYMEX heating oil in the L.A market. Bay CARB diesel slid 5 cents to even with June heating oil.
Diesel in Portland rose 8 cents to 15 cents a gallon over June heating oil. (Reporting by Erwin Seba. Editing by Andre Grenon)