UPDATE 1-Shell to pay $19.5 mln for California violations

* California AG investigated 1,000 Shell gasoline stations

* Shell failed to maintain gasoline tanks properly -AG

* Shell admits no liability, pleased to reach settlement

OAKLAND, Calif., Nov 6 (Reuters) - California was awarded $19.5 million in a settlement against Royal Dutch Shell Plc's (RDSa.L: Quote, Profile, Research) U.S. unit for not storing fuel properly at filling stations in the state, Attorney General Jerry Brown said on Friday.

"Shell Oil company disregarded the state's underground fuel storage and hazardous waste laws, committing hundreds of environmental violations at its gasoline stations across California," Brown said in a statement.

The attorney general's office, along with the California State Water Resources Control Board, investigated more than 1,000 Shell stations.

In 2007, an inspector in Martinez, California, found that a Shell station next door to the Contra Costa County Hazardous Materials Program's office failed to properly maintain the required leak detection monitoring system for its gasoline tanks, the attorney general's statement said.

Apart from paying $19.5 million in penalties to government agencies and legal costs, Shell must take a series of steps to improve spill and alarm monitoring and hazardous waste management at its stations, according to the judgment signed in Alameda County Superior Court in Oakland.

"While admitting no liability, Shell is pleased to reach this settlement and has been working cooperatively with the State of California since 2006 to resolve this matter," Shell said in an emailed statement.

The company said it had made great strides to improve its underground storage tanks, and that many of the measures outlined in the settlement had already been implemented. (Reporting by Braden Reddall; Editing by Bernard Orr)