World oil prices firmed on Wednesday as dealers took their direction from a weaker dollar, but sentiment remained cautious over concerns about the US and eurozone economies, analysts said.
Brent North Sea crude for delivery in December rose 55 cents to $108.81 a barrel in London afternoon deals.
New York's main contract, light sweet crude for December or West Texas Intermediate (WTI), increased 38 cents to $85.76 a barrel.
"Amid a lack of notable fundamental news-flow, crude oil prices are edging higher so far today within their recent range, partly buoyed by some technical speculative buying as weakness creeps into the dollar," said Sucden brokerage analyst Myrto Sokou.
A weak dollar makes dollar-priced crude cheaper for buyers using stronger currencies, boosting demand and eventually prices.
Oil prices had traded mixed in earlier Asian deals amid concerns over that the US fiscal cliff of tax hikes and spending cuts could tip the world's biggest economy into recession -- and potentially ravage energy demand.
The looming fiscal cliff has dogged financial markets since the re-election last week of US President Barack Obama.
Adding to uncertainty was the eurozone finance ministers' delay to a decision on releasing the next instalment of Greece's much-needed bailout cash.
Obama was on Wednesday to give his first post-election press conference, used to likely address the subject of the fiscal cliff, as well as the sex scandal that brought down CIA chief David Petraeus.
Traders were also to digest US retail sales data and the publication of minutes from the Federal Reserve's most recent monetary policy meeting.
The oil market fell on Tuesday after the International Energy Agency cut its global crude demand forecasts, while OPEC said that global stockpiles were "very high".