Vienna - The basket price of the Organization of the Petroleum Exporting Countries (OPEC) retreated below the 70-dollar mark Monday, the Vienna-based cartel announced Tuesday.

One barrel (159 litres) of OPEC-produced crude fell to 69.24 dollars at the start of the week, 1.21 dollars lower than last Friday.

Last week the price moved about 70 dollars for the first time since October 2008.

OPEC's 12 member countries produce some 34 per cent of the world's oil.(dpa)