Oil prices rose today, at the end of a week in which they have tumbled as the dollar pushed the euro to 14-month lows.
New York's main contract, light sweet crude for June delivery rose 74 cents to $77.85 a barrel. Brent North Sea crude for June delivery gained 56 cents to $80.39 a barrel.
Oil prices slumped between late Monday and Thursday as the dollar struck 14-month highs against the euro on worries about the stability of the euro zone amid the Greek debt crisis.
They were also weighed down yesterday by a stunning sell-off on US financial markets and news of rising oil inventories in the US, indicating weakening demand in the world's largest energy consuming nation.
A stronger greenback makes dollar-denominated oil more expensive for holders of rival currencies, such as the euro, denting demand for energy.
Oil prices began the week strongly - reaching a 19-month high of $87.15 on concerns about a slick in the Gulf of Mexico and positive US economic indicators.
However, worries that the Greek debt crisis may spread to other vulnerable euro zone economies and affect the global economy was dampening investor sentiment.
Meanwhile in the Gulf of Mexico today, crews lowered a dome over the oil leak in a bid to contain the sea of crude moving perilously closer to the US coast.
The unprecedented operation is seen as the best hope in staving off the biggest US environmental disaster since the 1989 Exxon Valdez spill in Alaska.
The containment chamber is designed to cap oil discharge from the Deepwater Horizon oil rig operated by British energy giant BP that exploded on April 20, triggering the massive oil spill and killing 11 workers.
Since the explosion, nearly three million gallons of crude have spewed into the sea from a well below the rig.
