The price of US oil fell below $92 a barrel today.
Oil prices dropped on concerns about weakening global growth and demand for crude.
By early afternoon in Europe, benchmark crude was down $1.28 at $91.61.
The contract had closed at $92.89 in New York on Friday
In London, Brent crude was down $1.40 to $110.02 on the ICE Futures exchange.
New efforts to revive growth from central banks in Europe, Japan and the US have not been enough to overcome pessimism about the global economy's prospects.
When economic growth slows so does demand for fuel which typically results in lower oil prices. A reduction in energy costs can help boost economic growth further down the track.
Analysts said renewed concerns about a slowdown in the global oil demand weighed on market sentiment. The strengthening US dollar added further pressure to the oil market. A stronger dollar makes crude for expensive and a less attractive investment for traders using other currencies.
On Friday, the US Labor Department said that the unemployment rate rose in more than half of the country's states last month.
The World Trade Organisation, meanwhile, cut estimates for global trade growth for this year and next.
In another sign of pessimistic economic expectations, Germany's Ifo index of business confidence fell for the fifth month in a row.
