Oil prices plummeted at the end of last year because of the global economic and financial crisis, but has more than doubled since then, in part buoyed by OPEC's supply cuts.

On Wednesday, the benchmark WTI brand of crude oil for October delivery traded at $71.68 per barrel in New York, $0.58 above the previous day.

OPEC's basket price stood at $67.83 per barrel Tuesday.

While the cartel is aiming to reduce currently high oil stocks around the world, non-member Russia is increasing its oil exports and has overtaken OPEC member Saudi Arabia as the world's largest oil exporter, Russian newspaper Vremya Novostei reported.

'That surely doesn't make OPEC happy,' said Johannes Benigni at Vienna-based oil consultancy JBC Energy.