Oil prices plunged on Friday as the strengthening US currency dented investor enthusiasm for dollar-priced crude, analysts said.

New York's main contract, light sweet crude for April delivery, slumped 1.91 dollars to 80.29 dollars a barrel, extending earlier losses.

London's Brent North Sea crude for May delivery dived 1.83 dollars at 79.66 dollars.

"It's the euro sliding against the dollar ... everything is tumbling, so hence we are down in line with the broader market," said VTB Capital analyst Andrey Kryuchenkov.

The European single currency slumped on Friday as investors sought the safe-haven US currency amid uncertainty about international assistance for debt-plagued Greece.

The euro dived as low as 1.3503 dollars on Friday, down from 1.3603 dollars in late New York on Thursday.

A stronger US unit makes dollar-denominated crude more expensive for buyers using weaker currencies and so tends to dampen oil demand and prices.

Prices fell hard this week as traders tracked the dollar and Greek debt concerns, and shrugged off a widely-expected decision from the 12-nation OPEC oil cartel to maintain output levels.

Anxiety over the fate of Greek finances deepened as the European Union groped for common ground on how to ensure that Greece will be able to borrow money on financial markets at rates similar to those paid by its partners.

Clearly dissatisfied with what they see as a tepid EU response thus far, Greek authorities have made it clear they are prepared to go to the International Monetary Fund for help.

"Otherwise, little changed in the world of oil with market participants still digesting the bullish weekly report on US fuel inventories report and OPEC's decision to keep production levels unchanged," Kryuchenkov said.

OPEC left its output ceiling unchanged at 24.84 million barrels a day at a meeting in Vienna on Wednesday, citing uncertainty in the macroeconomic environment and global oil demand.

The cartel, which pumps 40 percent of world oil, said it would review the economic situation at its next scheduled meeting on October 14.

Also on Wednesday, the US Department of Energy said stockpiles of distillates, including diesel and heating fuel, fell more than expected, by 1.5 million barrels, in the week ending March 12.

Gasoline or petrol inventories sank 1.7 million barrels, topping forecasts.

In addition, fears that Beijing will take more steps to cool the booming Chinese economy also hit sentiment this week because China is the second biggest global oil consuming nation after the United States.