Brent crude fell to its lowest level in 15 months on Tuesday, pressured by the prospect of slowing oil demand growth in China and Europe, while a strong dollar and ample supplies pressured U.S. oil prices.
Oil prices on both sides of the Atlantic have been in steady decline since the end of June as concerns faded over supply disruptions from Iraq, Libya and Russia. Continued supply from key producing regions and tepid demand has left global markets well stocked.
The euro sagged on Tuesday to fresh one-year lows against the dollar on bets the European Central Bank will do more to help a wobbly euro zone economy, while the pound fell to a near five-month low versus the greenback on worries about a Scottish secession.
Further pressure came from the prospect of resuming oil supplies from the Buzzard field in the North Sea and discouraging economic data from Europe and China. China's factory sector growth slowed to a three-month low last month.
Demand for physical crude has withered in recent months, creating a glut in Asia and the Atlantic basin and causing the futures market to flip into contango, in which oil for delivery in the future is priced higher than that for immediate delivery.
--By Reuters, with CNBC.com