Houston: UK oil major BP has uncovered a spill on a pipeline in Alaska, which, following major corrosion and resulting spills revealed in 2006 at the field, is likely to raise the ire of regulators.

While BP has yet to determine the cause or release the scale of the spill, it has said it occurred on a pipeline feeding into Prudhoe Bay, Alaska, the biggest oilfield in North America, and could have an impact on production. The field usually produces 400,000 barrels a day.

"We are working in a Unified Command with the Alaska Department of Environmental Conservation and the US Environmental Protection Agency to stop the leak and begin the clean-up," said Steve Rinehart, BP spokesman.

"The leak rate is very slow; the affected area is not growing."

US regulators have yet to comment on the spill.

Scrutiny

Prudhoe Bay has been under heightened scrutiny by regulators since widespread corrosion was uncovered in 2006, briefly shutting the entire field as the authorities ordered BP to replace corroded pipelines.

The scrutiny is part of a broader watch placed on BP after string of problems across its US operations led it to agree in 2007 to three years' probation and to pay fines totalling 0 million (Dh1.4 billion) to US authorities to settle violations linked to the oil pipeline leaks, a refinery explosion in Texas and fraud in energy trading.

In October, the US government said BP still had "systemic safety" issues four years after the explosion at its Texas City refinery killed 15 people and injured 170 and issued a record .4 million in proposed fines on the group.

Jordan Barab, acting assistant secretary of the US labour department's Occupational Safety and Health Administration, said then that, in spite of Lord Browne being replaced as BP chief executive after the blast, BP continued to violate US safety regulations under the leadership of Tony Hayward.

BP has denied continued problems at the refinery, saying it is in compliance with the law and contesting the proposed fine.
That BP now has a spill under Hayward is likely to raise concerns among investors that the problems BP sought to draw a line under with Lord Browne's replacement remain inside the company.

The spotlight on BP's US operations will continue into next year, when the US Chemical Safety Board, which conducted a two-year investigation of the refinery after the 2005 blast, is to release a report into a subsequent investigation at the refinery, launched in February 2008, after more deaths at the facility.