World oil prices slumped today after the euro hit a new one year low against the dollar amid worries about debt-laden Greece which shook global financial markets. Brent North Sea crude for June delivery tumbled $2.56 to $86.38 a barrel in London trade. New York's main contract, light sweet crude for June, dropped $2.84 to $83.35. Financial markets have come under heavy pressure after euro zone finance chiefs over the weekend approved an unprecedented three-year package of loans for debt-ridden Greece. Of the €110 billion to be made available to Greece, the euro zone is set to provide €80 billion and the International Monetary Fund €30 billion. In a policy U-turn, the European Central Bank agreed to accept Greece's junk-rated government bonds as collateral for loans. Aside from Greece, the oil market has also this week been gripped by the Deepwater Horizon oil rig disaster in the Gulf of Mexico. The rig, operated by British energy firm BP and owned by US contractor Transocean, sank on April 22 - two days after a massive explosion killed 11 workers.