Oil prices have fallen by more than a third since June as increasing production in North America from shale oil has overwhelmed demand at a time of sluggish global economic growth.
Ministers from the Organization of the Petroleum Exporting Countries had been discussing whether to agree a production cut at their meeting in Vienna.
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Benchmark Brent futures were down by $2.96 a barrel at $74.79 by 1520 GMT, after hitting a low of $74.36, their lowest since August 2010.
U.S. crude was at $71.07, down $2.62.
"Oil prices are now completely in the hands of the market," Dominic Chirichella, director of New York-based Energy Management Institute, told Reuters Global Oil Forum.
Kuwaiti Oil Minister Ali Saleh al-Omair said there would be "no change" to OPEC's existing oil production target following the meeting.
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The cartel will meet again in June next year, said an OPEC delegate. Ehsan Ul-Haq, senior oil market consultant at KBC Energy Economics, in Vienna for the OPEC meeting, said a KBC report expected oil prices stay under $80 a barrel.
"The probability of oil prices going below $70 a barrel is 20 percent, remaining in a range of $70-80 a barrel is 40 percent," he said.