Singapore - Oil eased in Asian trade on Monday afternoon but political instability in Libya and the Middle East are keeping upward pressure on prices.
New York's main contract, light sweet crude for delivery in May, dipped 38c to $105.02 per barrel while Brent North Sea crude for May lost 14c to $115.45, with both contracts giving up gains in the morning.
"Right now it is night time in these countries (in the Arab world), and markets have no fresh pictures from Libya and Syria," said Jason Feer, analyst for Argus Media energy market researchers in Singapore.
"Basically it is just the spread of political instability. Over the weekend, it got a lot worse in Syria and Yemen," Feer said.
Rebels in Libya were pushing west towards the capital Tripoli after coalition airstrikes on Sunday hit Sirte, the hometown of leader Moamer Kadhafi.
Anti-government forces have started retaking towns they lost to government forces last week, and have promised that their uprising would not further hamper oil production in areas under their control.
And a representative said the opposition plans to begin exporting oil "in less than a week".
"We are producing about 100 000 to 130 000 barrels a day - we can easily up that to about 300 000 a day," Ali Tarhoni, the rebel representative responsible for economy, finance and oil, told a news conference at the weekend.
Oil-rich Libya was producing 1.69 million barrels a day before the unrest, according to the International Energy Agency. It is now producing 400 000 barrels a day.
In Syria, security forces strove to restore order in the northern city of Latakia on Sunday, after two days of chaos that left 15 dead and more than 150 injured in an anti-government uprising that began earlier this month.
And in Yemen, embattled President Ali Abdullah Saleh said he does not want to cling on to power but warned that only dialogue can save the country he has ruled for three decades from sliding into civil war.