Crude oil futures witnessed mixed trade in November as supply outages in Libya lent support to Brent futures while higher stockpiles in the US pulled down US futures.
The January Brent contract dropped $1.17 to finish at $109.69 a barrel on 29 November. Prices rose about 0.8% for the month.
The January US crude oil contract added 42 cents to finish at $92.72 a barrel on 29 November. Prices dropped 3.7% for the month.
Around 85% of Libya's oil is exported to Europe and its biggest customer in the region is Italy.
Opec member Libya's oil production has slumped to around 1.25 million barrels per day (bpd) from 3.1 million bpd in 2010, before the revolution.
The country has suffered oil and gas supply outages since July this year. Protesters demanding more political rights and strikes over pay have hampered energy production and exports from the country, which holds Africa's biggest crude reserves.
In the US, crude oil supplies rose for the 10th successive week, according to government data released on 27 November.
Ole Hansen, head of commodity strategy at Saxo Bank said in a note to clients: Lower prices are a result of "the continued rise in production in the US from non-conventional production techniques."
The US supply infrastructure has failed to match rising production, which now exceeds 25 million barrels a day. With crude oil not reaching refineries, supplies are building up as a result of bottlenecks, putting prices under pressure.
"Refinery demand has begun to pick up but whether it will be enough to clear some of the supply glut over the coming months remains to be seen," Hansen added.
Shale oil production in the US is expected to push the nation past Russia as the world's top oil producer by 2015, the International Energy Agency said earlier.
The US, the world's leading oil consumer, produced more crude oil than it imported in October, a first in nearly 20 years, according to government data.