At 04:00 GMT. the price of September futures for North Sea petroleum mix of mark Brent has fallen by 0.31 percent, that is to $48.89 per barrel, and the the price of August futures of WTI crude oil fell by 0.55 percent to $47.38 per barrel.
On Thursday, the United Kingdom held a referendum to determine whether or not the country should leave the European Union, with over 50 percent of the UK public voting in support of Brexit.
Numerous opinion polls published on the eve of the referendum vote showed the quantitative superiority of Brexit opponents and many investors and analyst were confident that the outcome of the UK referendum will be that the country will stay in the EU.
Following the fist results which showed that the Leave camp was in the leading position, oil prices fell by 6 percent.