International marker Brent crude traded 25 cents higher at $22.12 a barrel after the comments on Wednesday at a conference in Houston.

Naimi said there was no chance output curbs would be lifted before an agreement expires at the end of March and that the cuts might even be extended for the second quarter if necessary.

Iran's Opec governor Hossein Kazempour Ardebili on Thursday said his country would support an extension if excess stockpiles remained in place.

``If the market is going to stay weak and if stocks are not withdrawn adequately, yes, we are for an extension of the current level of production,'' Ardebili told Reuters from Tehran.

Opec last March agreed to remove 4.3 million barrels a day of supply from the 75 million barrel-a-day world market for a year in an effort to lift prices from less than $10 a barrel.

The restrictions sent Brent prices rocketing to a peak of $24.30 two weeks ago before speculators starting taking profits from the eight-month-long rally.

Naimi said global stockpiles of surplus oil were not yet falling fast enough and what he called real demand had yet to pick up.

``I think inventories were just built too high in 1998 and the beginning of 1999. I believe they are coming down but they are not coming down fast enough, partly because real demand has yet to pick up,'' said Naimi.

``It all depends on what things look like in March but it is not unreasonable that production will be maintained at that level,'' he added.Saudi Arabia is Opec's most influential member country and together with Venezuela and non-Opec Mexico has been the driving force behind the current oil supply curbs.

Before Naimi's speech prices were undermined by latest data from the United States on inventories of crude and petroleum products.

The US department of energy information and administration said national crude stocks rose 3.4 million barrels to 300.7 million in the week to October 15. But distillate and gasoline stocks fell.

The United States consumes a fifth of world oil so the stock data is watched closely as a barometer of Opec's success in draining world inventories.