* Dollar firms, halting boost to oil
* Saudi oil minister sees $70-$80 as "ideal"
* French strikes boost oil products
* Coming Up: OPEC meeting Thursday (Updates prices, adds details)
By David Sheppard
NEW YORK, Oct 11 (Reuters) - Oil prices slipped towards $82 a barrel on Monday, retreating from a five-month high hit last week, on signs prices may have run ahead of demand.
Saudi Arabia Oil Minister Ali al-Naimi said prices between $70 and $80 a barrel were "ideal" as he arrived in Vienna ahead of OPEC's meeting on Thursday, indicating the producer group's most powerful member has no plans to pursue higher prices.
Analysts and traders said the fillip to oil prices caused by expectations of further quantitative easing in the United States, which helped raise U.S. crude as high as $84.43 a barrel last week, might have run its course as the dollar firmed on Monday.
U.S. crude for November delivery <CLc1> fell 45 cents, or 0.54 percent, to settle at $82.21 on Monday. Prices slipped further in post-settlement trade to hit a low for the day of $81.85 a barrel,
In London, ICE November Brent crude <LCOc1> fell 32 cents to settle at $83.71 a barrel, before slipping further to $83.38 a barrel by 4 p.m. EDT (2000 GMT).
"The big factor in the oil market in the past couple of weeks has been the pricing in of QE2," said Mike Wittner, an oil analyst at Societe Generale in London, who credited oil's sustained breakout above $80 at the end of last month to expectations of QE2.
"However, this pricing in may be coming to an end."
Expectations of QE2 have weakened the dollar, increasing the prospect that U.S. inflation will rise. A fall in the greenback boosts the dollar value of oil, which is usually traded in the U.S. currency. However, on Monday the dollar's recent downward fall paused. <.DXY>
Ahead of Thursday's production meeting of the Organization of the Petroleum Exporting Countries, Saudi Arabia, the world's largest oil exporter and the group's most powerful member, said the market was well supplied.
"I am comfortable with economic growth. The market is very well balanced," Saudi Oil Minister Naimi said.
OPEC was unlikely to change oil output targets at this week's meeting, delegates told Reuters on Sunday, while Qatar said current oil prices posed no harm to the world economy.
Oil prices for most of this year have stayed in a price range of $70 to $80 a barrel -- judged by OPEC to be high enough for producers who need to invest and low enough not to damage the world's economy.
CHINA TIGHTENS
Oil was relatively unmoved by the news that China, the world's largest energy user according to the International Energy Agency, had raised the required reserves of its four leading state banks to drain cash from the economy. [
]Amrita Sen, a commodities analyst at Barclays Capital in London, said the impact on China's energy demand would be muted.
"Given how energy intensive the Chinese economy is, even with some soft landing we do not expect this to change," Sen said.
The market will seek further clues to developments in the global economy from the release of the minutes for the last U.S. Federal Reserve meeting on Tuesday, China trade data on Wednesday and U.S. retail sales for September on Friday.
(Graphic of Reuters-Jefferies CRB index: http://link.reuters.com/kew48n)
FRENCH DISRUPTION
Prices took some support as a strike at France's top oil port of Fos Lavera continued into a 15th day on Monday. The nearby La Mede oil plant said over the weekend it had half idled its capacity and will fully shut down in a couple of days because of the disruption to supplies. [
]Workers at Petroplus's 154,000-barrel-per-day Petit Couronne refinery in northern France also started a rolling 24-hour strike over pensions, blocking fuel supplies and reducing production.
Disruptions to the supply of gasoline and diesel in France have boosted oil product prices and helped underpin the broader market, but some analysts cautioned that lower refinery operations could ultimately weigh on crude prices as less is used for processing.
Iran increased its official reserves estimate by 18 billion barrels to 150 billion barrels on Monday, ahead of Thursday's OPEC meeting. [
]The move followed the decision a week ago by Iraq, a fellow OPEC member, to raise its reserves figure to 143 billion barrels. [
]However, Olivier Jakob of consultants Petromatrix in Zug, Switzerland, was skeptical that Iran's news would have much effect on oil prices.
"Everything out of Iran is taken with a pinch of salt. It was a little bit of a reaction to the Iraqi announcement," he said.
(Additional reporting by David Turner in London and Alejandro Barbajosa in Singapore and the OPEC Newsroom in Vienna; Editing by Walter Bagley)