NEW YORK (CNN/Money) - Oil prices closed lower Monday after reaching record highs as Norway ordered an end to a strike that threatened to shut down the flow of oil from the world's No. 3 exporter.

Crude for December delivery closed down 63 cents at $54.54 on the New York Mercantile Exchange, after setting a new trading high of $55.67 a barrel overnight.

December Brent oil futures closed down 44 cents to $50.78 a barrel in London, after setting a record high at $51.90 in active trading.

Prices eased after Oslo's government intervened to end a strike by rig workers, averting an escalation that threatened to shut all of the country's 3.0 million barrels per day of oil output.

The Norwegian Shipowners Association threatened Monday to lockout employees, expanding a work stoppage that started with offshore oil rig workers there four months ago. The lockout would start at midnight Nov. 8, and could cut off the full 3 million barrels a day that normally flows from the country. The existing labor dispute has cut off only about 55,000 barrels per day.

Norway's government previously has stepped in to end oil labor disputes when there was a widespread threat to production. Union officials said the new lockout threat was a ploy to provoke the government to intervene.

But any threat of disruptions in supply in the tight market is likely to drive oil up to new records, said Peter Beutel, oil analyst and president of Cameron Hanover.

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"The thing about a bull market is everything looks bullish," he said.

Beyond the Norwegian situation, traders remain concerned about declining inventories of home heating oil in the United States, according to Beutel.

U.S. heating oil prices remained close to record highs, being little changed at $1.594 a gallon.

Heating oil supplies normally build in October, but the shutdown of some refinery capacity in September due to Hurricane Ivan hitting the U.S. Gulf Coast is still being felt, said Beutel.

"Normally refineries shut down for maintenance in September, but that's done in a staggered manner," he said. "When all these refineries were shut down due to Ivan, they were kept down for maintenance. It's possible they'll all come back in November and inventories will build then. But until that happens we're taking a wait-and-see attitude."  

-- Reuters contributed to this report