Oil prices rose on Wednesday as traders awaited the latest weekly inventory report on US energy stockpiles.
New York's main contract, light sweet crude for delivery in January climbed 44 cents to $88.37 a barrel.
Brent North Sea crude for February advanced 76 cents to $109.60 a barrel in London midday deals.
The US Department of Energy was to publish its inventory report one day after traders were heartened by data from the private American Petroleum Institute (API) that revealed a sharper-than-expected fall in US crude stockpiles.
"API crude stocks dropped over four million barrels, which should support oil prices," Nick Trevethan, senior commodities strategist at ANZ Research, told AFP.
The fall was far steeper than the 1.7 million-2.3 million barrel drawdown projected by various analysts. A fall in US crude inventories indicates a pickup in energy demand in the world's largest oil consumer.
Market confidence has been boosted also by hopes of a breakthrough in Washington on averting the "fiscal cliff" of tax hikes and spending cuts due to come into effect at the start of January.
The US economy will likely tip into recession if a new deal to cut the country's deficit with less swingeing measures is not found.
President Barack Obama and Republican House Speaker John Boehner have in recent days stepped up negotiations, with both sides narrowing their differences and providing concessions on spending and taxes.