May 14 (Bloomberg) -- Crude oil gained for a third day after incidents at refineries in Europe and the U.S. raised concern gasoline might run short this summer.

Preem Petroleum AB, Sweden's largest oil company, evacuated workers at its refinery in Gothenburg, Sweden, after a fire broke out yesterday. Valero Energy Corp. said yesterday emergency flaring occurred at its refinery in Texas City, Texas, on May 12, at least the third incident at the plant this month.

``Gasoline is the key focus,'' said Jonathan Barratt, the managing director of Commodity Broking Services in Sydney. ``The market is surely concerned as we are driving to summer time,'' when demand peaks in the U.S., the world's biggest oil consumer.

Crude oil for June delivery rose as much as 70 cents, or 1.1 percent, to $63.07 a barrel in after-hours electronic trading on the New York Mercantile Exchange. It traded at $62.96 at 1:49 p.m. in London.

The fire at Gothenburg started while the refinery was being brought back into operation after five weeks of maintenance. It was put out yesterday. Other parts of the refinery are still starting up, said Thomas Oegren, a Preem spokesman. The plant, which has a capacity of about 100,000 barrels a day, produces heating oil, aviation fuel, diesel, butane and propane.

In Norway, Norsk Hydro ASA trimmed its forecast for oil and gas production this year by 3.3 percent to 585,000 barrels a day after the Kvitebjoern field was closed and two offshore sites were delayed. The reduction came after Statoil ASA, Norway's biggest oil company, cut its output goal on May 10 after closing Kvitebjoern, which it operates.

African Disruption

An Agip SpA oil worker was kidnapped by gunmen in southern Nigeria today, Italy's Eni SpA said. Chevron Corp., the second- biggest U.S. oil company, said May 11 it was evacuating hundreds of contractors and suspending some offshore drilling projects in Nigeria because of security threats.

Chevron's Nigeria venture yesterday resumed pumping 42,000 barrels a day at the fields of Dibi, Utonana, Makaraba and Abiteye that had been halted since May 7, said Femi Odumabo, a spokesman for Chevron.

At the Funiwa field, 15,000 barrels a day remains halted after militants kidnapped six expatriate Chevron workers on May 1, Odumabo said. Four more Chevron contractors were abducted May 9 by unknown assailants.

Brent crude, the benchmark for Nigeria's crude, rose 2.3 percent last week after militant attacks cut in half the output from an Eni SpA export terminal in Nigeria and a fire shut a Total SA field in the Republic of Congo.

Brent crude oil for June settlement gained as much as 68 cents, or 1 percent, to $67.51 a barrel on London's ICE Futures exchange. It was at $67.40 at 1:48 p.m. in London.

Brent crude's premium over West Texas Intermediate, the New York benchmark, widened to as much as $5.13 a barrel today, a four- week high, after supplies from Africa fell.

Total's Field

Total, Europe's third-largest oil company, said it may restore output at its 60,000-barrel-a-day N'kossa field in the Congo within two weeks. Eni cut production in Nigeria by 98,000 barrels a day last week after attacks on pipelines to the Brass export terminal.

Nigeria, once Africa's largest oil producer, has lost about 815,000 barrels a day of output, or about a third of its capacity, because of attacks on pipelines and oil fields, according to the Paris-based International Energy Agency.

U.S. stockpiles are the lowest for this time of year in 16 years and gasoline may remain the ``primary driver'' of oil prices, the International Energy Agency said last week.

``A lot of people are looking at close to $4 a gallon'' at the pump for gasoline, Commodity Broking's Barratt said. ``There is a tremendous shortage. I can see prices continue to try a lot higher.''

Gasoline for June delivery was trading for $2.37 a gallon after rising 2.6 cents to $2.3521 May 11. Prices rose 6.1 percent last week as refinery shutdowns and rising demand heightened concern the U.S. might not have enough fuel this summer.

``The U.S. needs to pump up gasoline production and increase imports from Europe and Asia,'' said Tetsu Emori, the chief commodities strategist at Mitsui Bussan Futures Ltd. in Tokyo.

Stockpiles Grow

Gasoline stockpiles rose for the first time in 13 weeks to 193.5 million barrels on May 4, according to the U.S. Department of Energy. That's still 8 percent less than the five-year average for the period. Supplies now equal 21.7 days of demand.

Expressed in U.S. dollars, West Texas Intermediate, the New York-traded benchmark, has fallen about 9 percent in the past 12 months. Oil has dropped 14 percent in euros, 14 percent in British pounds and 1 percent in yen.

The Organization of Petroleum Exporting Countries ``could raise its production rate, but it doesn't have a reason for doing so,'' said Ulrich Steiner, a commodity analyst with Bank Clariden Leu in Zurich. ``Prices are between $55 and $65 for the barrel. Everybody can live with that -- producers and consumers.''

Saudi Aramco, the world's largest state oil company, will cut Arab Light crude oil exports to Asia next month for the first time in at least three months as part of an overall supply reduction to the region, said three refinery officials who asked not to be identified. The producer has been reducing Arab Medium and Arab Heavy sales by 9 to 10 percent of total contracted volumes.

To contact the reporter on this story: Eduard Gismatullin in London at egismatullin@bloomberg.net

Last Updated: May 14, 2007 08:58 EDT