Alaska's main oil pipeline was still expected to restart this week after a spill on Saturday forced it to shut down, idling 12 percent of U.S. oil production, a source familiar with its operations said.

Trans Alaskan Pipeline System operator Alyeska expects to bypass a leaky area along the 600,000 barrel-per-day, 800-mile line by installing a substitute stretch of pipe, the industry source told Reuters. Alyeska will await approval from the U.S. Department of Transportation (DOT) before resuming operations, he added.

On Monday, DOT's Pipeline and Hazardous Materials Safety Administration said the pipeline would not need its approval to be repaired and restarted. Regulatory approval sometimes delays pipeline restarts.

TAPS leaked around 10 barrels of oil into the basement of a pump station and was shut down over the weekend. Although the shutdown was expected to be short, it helped drive gains in world oil prices this week.

U.S. benchmark light crude for February delivery rose 86 cents to $90.11 a barrel as of 9:37 a.m. EST (1437 GMT) after settling 1.4 percent higher on Monday. European benchmark Brent rose more sharply, gaining $1.13 to $96.83.

TAPS is usually able to restart quickly, even after a spill. Last May, when several thousand barrels of oil spilled into a pump station, the line was forced to shut down for less than four days.