Workers expected to return to work at Scottish oil refinery

LONDON—Workers will return to the Grangemouth refinery in central Scotland on Tuesday morning, their union said, ending a 48-hour strike that forced the closure of a major North Sea pipeline system.

But UNITE, Britain's largest union, said further industrial action remains possible unless refinery owner Ineos backs down in a dispute over pensions.

The strike at the refinery led to the closure of the Forties Pipeline System, which brings more than 700,000 barrels of oil a day in from the North Sea to BP PLC's Kinneil plant.

Kinneil is powered from the Grangemouth site.

Although work at the refinery was set to resume at early Tuesday, bringing the interconnected network of pipelines back online is expected to take several days.

"It's not a case of having one big master valve you can just turn on," BP spokesman David Nicholas said Monday. He declined to say exactly how long the process would take, but Ineos Group Ltd. spokesman Mark Killick said it would be about three or four days before the system was fully operational.

Killick added that restoring operations to the refinery could take as long as a month if there were problems reintroducing heat and pressure into the pipes.

UNITE has left open the possibility of another strike -- something the British and Scottish governments said they were doing everything they could to avoid.

The pipeline disruption is costing the British economy 100 million pounds ($200 million) a day, according to industry estimates, and officials have shipped extra fuel to Scotland to ease pressure on the country's gas stations.