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• 'We expect commodity prices to rise in 2011'

OSLO (AFP) - Norway, one of the world's leading exporters of oil and gas, said on Thursday its undiscovered reserves were 21 percent lower than estimated owing partly to disappointing drilling results.

"Production is declining in spite of vigorous (prospecting) activity. Not enough new reserves are found to offset current oil and gas production," the Norwegian Petroleum Directorate said in its annual review.

"The volume of undiscovered resources has been reduced from 3.3 to 2.6 billion standard cubic metres of oil equivalents," or from the 20.8 billion barrels of oil equivalent (boe) estimated in 2006 to 16.4 billion boe, it added.

Oil prices rose for a fourth consecutive day in Asian trade Thursday on a sharp slump in crude stockpiles, indicating strong demand in the world's biggest economy, analysts said. New York's main contract, light sweet crude for February delivery, gained two cents to reach $91.88 a barrel in the afternoon.