Valero to Fight Patent Lawsuit by Unocal

Gasoline producer Valero Energy Corp. said Thursday that it will fight a multimillion-dollar lawsuit filed by Unocal Corp. that alleges it violated Unocal’s clean-air gasoline patents.

The patents are on a process to refine gasoline that meets Environmental Protection Agency requirements, used at a third of the nation’s pumps to combat smog.

San Antonio-based Valero is one of the nation’s top producers of gasoline and other fuels. It produces about 2 million barrels a day from its 12 U.S. refineries.

Critics say Unocal’s patents make for an unfair monopoly on the EPA’s cleaner-burning gasoline, and are partly responsible for higher fuel prices.

Exxon Mobil Corp. last year successfully urged a Federal Trade Commission investigation of Unocal’s fuel patents, claiming they were an unfair monopoly. The investigation is ongoing.

Unocal also said Thursday that it would report a fourth-quarter loss as it writes down the value of Gulf of Mexico sites by $86 million in response to lower energy prices.

Excluding items, profit would be in line with the 24-cent average estimate of analysts surveyed by Thomson Financial/First Call, Unocal said.

Unocal will report earnings Tuesday. Unocal shares rose 42 cents to close at $34.62 on the New York Stock Exchange.