Sept. 14 (Bloomberg) -- OPEC forecast demand for its crude oil will fall by 216,000 barrels a day next year and said the rising cost of credit may slow global economic growth.

The Organization of Petroleum Exporting Countries, whose members produce more than 40 percent of the world's oil, next year will need to supply an average 30.8 million barrels of output a day, the group said in its monthly report. The ``call'' on OPEC crude will average 31 million barrels in the fourth quarter of this year, 100,000 barrels a day more than in 2006.

``Financial instability could negatively affect the real economy in the U.S. and globally, with a subsequent impact on oil demand,'' today's report said. ``However, it is still too early to gauge the full impact of recent developments.''

Oil prices breached $80 a barrel in New York for the first time on Sept. 12, a day after OPEC decided to increase its output by 500,000 barrels a day. Speculation that global stockpiles may be drained before the end of the Northern Hemisphere's winter has so far trumped concern the impact of financial market volatility will cut demand.

``The additional 500,000 barrels isn't going to make much of a dent,'' said Simon Wardell, energy research manager at Global Insight Inc. in London. ``We think any fallout from the financial turmoil will be next year. That points to an increase in demand in the fourth quarter and we just simply don't have enough supply to go around.''

OPEC left unchanged its estimate for global oil demand growth in 2007 at 1.5 percent, or 1.3 million barrels, to 85.7 million barrels a day. Demand next year will grow by 1.3 million barrels to 87.1 million barrels a day, ``in line with the previous forecast,'' the report said.

Mexico, Azerbaijan

The Vienna-based group cut its estimate of 2007 oil supply growth from outside OPEC by 20,000 barrels to 840,000 barrels a day on lower third-quarter output in Mexico and Azerbaijan. Total non-OPEC supply this year will average 50.31 million barrels a day. In 2008, supplies from non-OPEC producers will increase by about 1 million barrels a day, the report said.

The 10 OPEC members with production quotas set a production ceiling of 27.253 million barrels a day at this week's meeting. Saudi Arabia, the world's largest oil exporter, has a limit of 8.943 million barrels a day, the group said on its Web site.

``They did the politically correct thing, but in terms of what it's going to do to the market price, it's too little, too late,'' Ray Carbone, president of Paramount Options and a trader on the New York Mercantile Exchange for 20 years, said yesterday. ``One million barrels a day would have put their prices under too much threat if there is a global downturn.''

Product demand for gasoline and diesel fuel will remain ``strong'' because of continued refinery glitches and falling gasoline stockpiles in the U.S., the report said. U.S. gasoline supplies were 5.7 percent below the five-year average last week, the Energy Department said.

Global refinery utilization rates are expected to decline in the next three months, ``particularly in the Atlantic Basin,'' the report said.

To contact the reporter on this story: Bill Murray in London at wmurray1@bloomberg.net

Last Updated: September 14, 2007 09:02 EDT