UPDATE 5-Oil slips on profit-taking during holiday lull
* S. Sudan says rebels seized capital of key oil-producing region
* Libya should use force to reopen oil ports - oil min
* Total refineries in France enter 11th day of strikes
NEW YORK, Dec 23 (Reuters) - Crude oil futures fell on both sides of the Atlantic on Monday as traders booked profits following three days of gains.
Trading volume was light ahead of the Christmas holiday.
"I think we're falling back on a little profit-taking," said Addison Armstrong, senior director of market research at Tradition Energy in Stamford, Connecticut. "The few traders who are in the office are likely to be booking profits instead of building a new position."
February Brent crude fell 10 cents to $111.67 a barrel by 11:03 a.m. EST (1603 GMT) after gaining 2.7 percent last week. It touched a two-week high of $111.93 earlier in the session.
U.S. crude for February delivery fell 33 cents to$98.99 a barrel.
The spread between the two benchmarks widened slightly to $12.68.
Brent's losses were capped by refinery strikes in France and internal strife in South Sudan.
Escalating tension and violence in South Sudan threatened its 245,000 barrels per day (bpd) oil output. The government said on Sunday rebels had seized the capital of a key oil-producing region.
This could add to the more than 1 million bpd of lost supply from Libya where ports were shut by a group demanding greater autonomy.
South Sudan's ambassador in Khartoum said on Sunday that oil was flowing normally, although the country's main investor China National Petroleum Company has evacuated its oil workers from the fields to the capital Juba.
Libya's oil minister said on Saturday force should be used to reopen oil ports in the eastern part of the country which have been closed for five months.
Workers at three of Totals' five refineries in France entered an 11th day of strikes, idling around 509,000 bpd of refining capacity and adding further uncertainty to the oil demand and supply picture in the region.