Oil fell below $58 a barrel this evening, pressurised by weak global demand and by gains in the US dollar against the euro.
US crude fell 99 cents to $57.63 a barrel, while London Brent fell 83 cents to $57.76.
The US dollar was slightly up against a basket of major currencies, having risen earlier following weak German economic data. A stronger dollar can limit investor demand for oil and other commodities.
US oil hit a six-month high above $60 a barrel on Tuesday, before weak demand outlooks halted the recent rally.
The International Energy Agency said on Thursday that world oil demand this year would record the sharpest annual decline since 1981 as the economy struggles to bounce back.
This came a day after the Organisation of the Petroleum Exporting Countries (OPEC) said global oil demand would drop 1.57 million bpd in 2009 to average 84.03 million bpd.
Despite falling demand for oil, OPEC, which has announced 4.2 million bpd of production cuts since September in a bid to tighten the market, also pumped more oil last month than in March, the IEA said.
