The worsening economic outlook in developed countries pushed the Organization of Petroleum Exporting Countries (OPEC) Tuesday to slash its global oil demand growth projections.

Predicting the faltering economies of the U.S. and Europe will cause a contraction in China and India as well, OPEC revised September's oil demand growth projections to 800,000 from 1.06 million barrels a day.

It expects consumption in 2012 will grow 1.19 million barrels a day to 89 million, set against a previous daily estimate of 1.27 million.

"Chinese oil demand is bound to uncertainty because of new government policies aimed at reducing transport fuel use. India's increase in retail prices is expected to play a major role in dampening oil consumption," OPEC's Vienna-based secretariat said in a report Tuesday.

This is the third month that OPEC has reduced its demand estimate based on threats to the global economy.

OPEC members anticipate global demand for their crude will reach 29.9 million barrels a day in 2011 and maintain that level until 2012. OPEC's crude oil total output in September registered only 27.24 million barrels a day, as against 27.31 million in August. Excluding Iraq, the group pumped 27.2 million barrels a day.

OPEC's members are Algeria, Angola, Ecuador, Iran, Iraq, Kuwait, Libya, Nigeria, Qatar, Saudi Arabia, the United Arab Emirates and Venezuela. It is responsible for supplying about 40 per cent of the world's crude supply.

The organization will meet again on Dec. 14 in Vienna.