Vienna - The basket price of the Organization of the Petroleum Exporting Countries (OPEC) gained slightly and settled at 56.37 dollars on Friday, the cartel announced Monday.

After dipping towards the end of last week, the price for one barrel (158 litres) of OPEC-produced crude oil inched upwards by 0.38 dollars on Friday.

OPEC's 12 member countries produce over a third of the world's crude oil.