The oil price of the Organization of the Petroleum Exporting Countries (OPEC) slipped to 71.97 dollars at the start of the week, its lowest value in the past five weeks, according to data published by OPEC on Tuesday, DPA reported.

The oil cartel's basket price settled 1.05 dollars lower on Monday than on the previous trading day.

Plans by US President Barack Obama to regulate the financial sector more tightly, as well as the prospect of a tighter Chinese monetary policy, have put oil markets under pressure in recent days.

OPEC's 12 member countries produce more than a third of global oil supplies.