New York's main contract, light sweet crude for delivery in December, fell five cents to USD 86.02 a barrel and Brent North Sea crude for December delivery shed 34 cents to USD 109.06.
"European markets are not showing any positive signs of economic recovery as they struggle to fight the fires burning in Greece and Spain currently," IG Markets said in a report.
Greece's budget paves the way for the European Union, International Monetary Fund and the European Central Bank to unlock a 31.5 billion euro (USD 40 billion) tranche of bailout funds for Athens.
Greece's unrelenting debt problems will top the agenda today when eurozone finance ministers discuss whether Athens has met all the conditions set by its international creditors to provide funds so it can stay afloat.
Without fresh funds, Greece risks default on Nov 16, when the government must repay a three-month treasury bill worth five billion euros.
In Spain, the completion of a bond-selling programme on Thursday all but ruled out a much-anticipated eurozone bailout for Europe's fourth largest economy this year.