Oil prices tumbled four percent on Monday, coming close to their 11-year low – amid fears that the global surplus could worsen in the coming months as producing countries engage in a pricing war.
Brent crude fell by four percent to below $36.40 (33 euros) a barrel for the first time since December 2008 and US West Texas Intermediate (WTI) sank almost three percent below $34.60 (31.4 euros) a barrel.
Brent traded only 14 cents above the lows last seen during the 2008 financial crisis of $36.20 (32.8 euros) a barrel.
Both benchmarks have fallen every day since OPEC abandoned its output ceiling earlier this month.
The organisation has been pumping near record levels of oil since last year in a bid to drive higher-cost producers such as US shale firms out of the market.
Supplies are expected to grow even more early next year as Iran increases production once sanctions are lifted.