Gasoline futures led the complex higher, rallying 3 percent, boosted in part by concerns about the slow return of some refinery operations following Hurricane Irene.

Further support for prices came after Chicago Federal Reserve Bank President Charles Evans said he favored strong central bank accommodation for a substantial period of time, as the US economy looks to be moving “sideways”.

Traders have been closely watching for any signs of more stimulus for the economy, which would spur investors into oil.

Crude got an additional boost following the release of notes from the August 9 policy meeting showed the Fed considered a range of actions, including the unprecedented step of tying interest rate policy outlook to a specific unemployment level.

Brent crude traded up US$2.14 to settle at a four-week high of US$114.02 a barrel, breaking over the 50-day moving average. US crude settled up US$1.63 at a three-week high of US$88.90 a barrel.