VIENNA: (AFP) – The OPEC group of petroleum exporting countries slightly lowered its forecast Tuesday for 2011 and 2012 crude oil demand, citing concerns for the economic health of developed countries.

In its monthly report, the cartel said demand for crude was expected to reach 88.14 million barrels per day (mbd) in 2011, down from a previous estimate of 88.18.

The new figure represented a rise in demand of 1.2 mbd from 2010, it said, as world oil prices hit multi-month lows.

New York’s main contract, West Texas Intermediate light, sweet crude for delivery in September, plunged in Asian deals to $75.71 a barrel — the lowest level since September 29, 2010. It later stood at $79.05, down $2.26 from Monday.

Brent North Sea crude for September dived as low as $98.74 a barrel, hitting a level last seen on February 8, before pulling back to $101.65, down $2.09.

For 2012, OPEC said it now forecasts a demand of 89.44 mbd, down from a previous prediction of 89.50 mbd.

“Economic worries along with high oil prices have affected OECD oil demand, leading to weaker-than-expected consumption during the summer driving season,” said the group, whose members provide about 35 percent of the world’s crude oil and has more than three-quarters of its reserves.

“Oil demand in the OECD is expected to continue its contraction after a temporary rebound last year,” OPEC said.

The Organisation for Economic Cooperation and Development groups 34 of the world’s most advanced economies.

OPEC cited the situation in the United States, which saw its “AAA” credit rating downgraded on Friday by Standard & Poor, as a particular concern.

“Should the situation see further deterioration in the US, then aggregate oil demand will see a further decline this year,” said OPEC of the world’s biggest oil consumer.

The Federal Reserve in June predicted slower growth in the US economy than previously expected for 2011 at between 2.7 percent and 2.9 percent — down from an earlier forecast of between 3.1 percent and 3.3 percent.

But OPEC said the impact from the S&P downgrade should be “low” in the short-term.

In the eurozone, the risk of the debt crisis swallowing Italy and Spain are counterbalanced by a rise in orders in the manufacturing industry, which should sustain the demand for oil, it added.

On the production side, OPEC said it had produced an extra 0.4 mbd last month.

Production reached 30.07 mbd, 0.7 mbd more than the level before the outbreak of the Libyan conflict.

Five months into hostilities, the country is yielding only about 50,000 mbd, down from 1.6 million mbd previously.

OPEC member states decided at a meeting in Vienna in June to leave the official output target at 24.84 mbd, where it has stood since January 2009.

Not counting Iraq, the only member country without a production quota due to unrest, OPEC is currently producing 27.39 mbd.