Oil prices were mixed this afternoon, dipping in London, weighed down by Portugal's debt crisis, but rising in New York as a results of the ongoing unrest in the Middle East and North Africa.
Brent North Sea crude for delivery in May fell one cent to $115.56 a barrel in London deals.
New York's main contract, light sweet crude for May, rose 78 cents to $106.51 per barrel.
The market is closely following the level of US gasoline (petrol) inventories ahead of the summer driving season in the United States, which starts in May.
Unrest in the Libya and the Middle East is seen as a crucial factor in driving crude prices.
Prior to the start of the unrest, Libya was producing 1.69m barrels a day, according to the International Energy Agency.
Output in the country has now almost ground to a halt, the IEA said earlier this month.
Elsewhere, anti-government demonstrations continue to be held in Yemen, Bahrain and Syria and there are fears that the unrest could spread to Saudi Arabia.
In Europe, all eyes are on today's EU summit, set to be dominated by rising expectations that Portugal could soon be forced to request a multi-billion-euro bailout.
