Rivals Sue Unocal Over Gasoline Patent

An angry rift in the oil industry moved into court Thursday when six oil companies sued Los Angeles-based Unocal Corp. over its sweeping patent for the cleaner-burning gasoline that will be required in California beginning next year.

The companies say Unocal’s patent is so broadly drawn that it could force all refiners in the state to pay huge royalties for formulas that the plaintiffs say should be in the public domain. The royalties could total a penny a gallon, or $80 million a year.

Unocal spokesman Barry Lane declined to comment on the suit.

The firms say that for the past decade, Unocal was part of an industrywide research effort to develop various formulations to meet the state requirements but that it surreptitiously also applied for the broad patent, approved in February, 1994.

Chevron, Atlantic Richfield Co., Exxon Corp., Mobil Corp., Shell Oil Co. and Texaco Inc. filed the suit to invalidate Unocal’s patent in U.S. District Court in Los Angeles.