Oil prices are hovering around $60 a barrel after Opec left output levels unchanged and the US reported a rise in American crude oil stocks.
Oil prices have fallen sharply in the past week
After dipping just below $60 a barrel, the price edged up slightly, with US light crude sitting at $60.27.
Supply problems still surround Iraq, Nigeria and Iran, and producers' group Opec decided on Wednesday to keep pumping oil at near capacity.
Crude supplies are at a six-year high in the US.
The US department of energy published figures on Wednesday showing stocks rose by 6.8 million barrels to 335.1 million last week.
Supply concerns in Iraq are being caused by the continuing violence there, while anti-government militants in Nigeria are attacking facilities in the main oil-producing region.
At the same time, unease continues over Iran's nuclear ambitions, in a growing international dispute that could lead to the introduction of United Nations sanctions, hitting Iranian oil exports.
These uncertainties come at a time when booming growth in the US, as well as emerging economies such as China and India, is also putting pressure on supplies.
Opec president Edmund Daukoru said output would remain the same but that the cartel would monitor it closely.
Opec members include Saudi Arabia, Iraq, Iran and Nigeria. The cartel provides more than a third of the world's oil.
Opec's output has consistently been more than 28 million barrels a day, and often close to 30 million a day, figures have shown.
That is approaching maximum levels and analysts warn that there is little slack in the system.