OSLO (Reuters) - About 25,000 barrels of oil spilled into the Norwegian sector of the North Sea at the Statfjord oilfield on Wednesday, field operator StatoilHydro and oil officials said.
The spill occurred in rough seas while oil was being loaded from a storage unit to a tanker, but the spillage has been halted, oil safety authorities said.
A meteorologist at the Storm forecasting centre said the spill may be drifting east to southeast. That could put it on a collision course with the southwest coast of Norway.
"This could be the second largest spill in Norwegian oil history," the Petroleum Safety Authority's (PSA) spokeswoman, Inger Anda, said. The biggest was a 75,000-barrel spill from the Bravo blowout in 1977.
By comparison, the Exxon Valdez tanker spilled about 240,000 barrels of crude off Alaska in 1989.
"During loading of oil from the Statfjord A platform in the North Sea about 4,000 standard cubic meters of oil was released into the sea," Norwegian energy group StatoilHydro said in a statement.
Neither production nor exports from Statfjord, the biggest oilfield ever found off Norway though now far off its peak, would be affected, StatoilHydro said.
Statfjord currently produces about 100,000 barrels per day and news of the spill initially helped to send oil prices higher.
The spill happened in rough weather while the tanker Navion Britannica was loading oil from a storage buoy, StatoilHydro said. The ship belongs to Vancouver-based tanker group Teekay Corp.
Winds at Statfjord are for the moment around 45 knots, and seas are around seven meters (23 feet), StatoilHydro said.
The Statfjord field lies about 200 km (124 miles) offshore, west of the port of Bergen near the UK boundary line in the North Sea.
The PSA said it established an emergency response centre.
The Storm centre official said southerly near gale to gale winds were expected in the area for the next 24 hours and seas of 4-1/2 to 7 meters and the spill seemed to be drifting east to southeast, but that could not be immediately confirmed.
StatoilHydro shares rose despite the spill and traded up 1.4 percent at 165 Norwegian crowns ($30.36) at 10:04 a.m. EST, outperforming a 0.2 percent rise in the Oslo bourse benchmark index and a 1.1 percent rise in the DJ Stoxx oil and gas index.
(Additional reporting by Wojciech Moskwa, Ole Petter Skonnord and Bart Noonan, Editing by Anthony Barker)