Global oil prices dropped as fears of potential US military strikes against the Syrian government subsided.
North Sea Brent crude oil prices for delivery in October hovered around $112 a barrel on 13 September. Benchmark US crude oil prices ended at $108.21.
Brent had earlier traded at $116.12 a barrel while US crude traded at $110.53 a barrel.
Concerns surrounding an impending US-led attack on Syrian President Bashar al-Assad's regime had boosted Brent crude prices to above $117 per barrel at the end of August.
Meanwhile, downbeat US retail sales data raised fresh concerns about the demand for the commodity in the world's leading economy.
The American economy is recovering, albeit at a slow pace. Government data showed that barring gasoline, automobiles and building materials, so-called core retail sales inched up 0.2% in August, after rising 0.5% in July.
Earlier in Libya, the government issued arrest warrants for protestors who have managed to cripple the country's oil industry.
Strikes over pay have hampered oil production and exports from Libya, which represents over 1.5% of global oil output. Prime Minister Ali Zeidan's government estimated the country was losing about $130m (£81m , €98m) in oil revenues each day.