Flat U.S. gasoline prices mask sharp spike in California

Oct 7 (Reuters) - The average price for a gallon of gasolinein the United States rose less than half a cent over the pasttwo weeks, masking a decline in most regions and a sharp spikein California prices, according to a widely followed survey.

Gasoline prices averaged $3.8375 on Oct. 5, up from $3.8338on Sept. 21, Trilby Lundberg, editor of the Lundberg Survey,said on Sunday.

Prices were down about 3 to 12 cents in most markets exceptthe West, she said.

While the overall U.S. average gas price was flat, theCalifornia average price at the pump jumped to $4.4992, up 38.79cents per gallon in the same two-week period ending Oct. 5,Lundberg said.

Even while U.S. crude oil prices eased during that time,refinery outages sparked higher prices, causing shortages atsome gas stations.

On Oct. 6, the average price in California for a gallon ofgasoline hit a record at $4.614, according to AAA.

But two gasoline price indicators - one in California marketproper and the other in the West region - showed signs thatprices were set to ease, Lundberg added.

The spot price in Los Angeles dropped 40 cents between Oct.3 and Oct. 5, from $4.2495 to $3.85 per gallon.

"Unbranded rack (gasoline), the second-most sensitive tochanges in supply," also saw a decrease, according to Lundberg.

"That price on Oct. 4 in the Western region was $4.0284. OnOct. 5 it was $3.9075, so that means it dropped by a bit over 12cents in one day."

Additionally, Exxon Mobil Corp's Torrance,California, refinery was back up and running after a poweroutage.

The current U.S. average for a gallon of regular gasoline at$3.8375, is still higher than a year ago, on Oct. 7, when theaverage price was $3.4192, Lundberg said.

"People are not looking at the date and calculating whetherit's interesting or not interesting, but it's not great forthose really watching costs, or those trying to get around inthis economy to find a job," Lundberg added.

According to the survey, which tracks 2,500 gas stationsnationwide in the lower 48 U.S. states, the most expensive gaswas in San Diego, at $4.55 a gallon. Drivers in Jackson,Mississippi, again paid the least at $3.43 per gallon, and twoweeks a gallon of gas there cost an average $3.52.

(Reporting By Jeanine Prezioso; Editing by Maureen Bavdek)

((jeanine.prezioso@thomsonreuters.com)(+ 1 646 2236241)(Reuters Messaging:jeanine.prezioso.reuters.com@reuters.net)(on Twitter@jeanineprezioso))