NEW YORK (CNN/Money) - Oil prices settled above $53 a barrel Friday, closing at a record high for the fourth straight session, as labor strife in Nigeria and Norway rekindled supply worries.

Also boosting prices Friday: concerns about terrorism in the wake of a deadly bombing in Egypt.

U.S. light crude for November delivery jumped 64 cents to close at $53.31 a barrel. In London, Brent crude for November delivery added 75 cents to $49.65.

Prices had gyrated earlier in the session, falling as low as $52.17.

"You're seeing some back and forth movement because after three straight up days, there's a strong tendency to take profits," said Phil Flynn, analyst with Alaron Trading. "But any prolonged labor disruption in Nigeria would be devastating."

The cancellation of a surprise strike by union workers in Nigeria alleviated some pressure on oil prices Friday, but a general strike set to begin Monday looms and may disrupt crude production in Africa's biggest exporter.

In Norway, oil rig workers said they will expand a three-month strike Saturday by closing another North Sea field and increasing the amount of output hit by 25,000 bpd. The move will take the amount of oil supply affected to 55,000 bpd.

Overall oil production from the North Sea has fallen sharply this year.

The decline is concentrated in the British sector of the North Sea where industry analysts Wood Mackenzie said average production for the first half of 2004 was 1.9 million bpd, down around 12 percent from the level of 2.166 million bpd a year ago.

In addition, a deadly attack on an Egyptian hotel popular with Israelis and a package bomb in Paris raised concerns about further terrorist action going into the weekend.

"These have people worried and investors don't want to hold short positions before the weekend," said Flynn.

Dealers were also concerned about foul weather in the Gulf of Mexico that forced the Louisiana Offshore Oil Port to cease oil tanker offloading operations temporarily, which could delay a rebound in national stockpiles.  

-- Reuters contributed to this report.