* U.S. crude futures extend 2010 intraday peak to $85.22
* North Sea Brent crude oil jumps to over $84 barrel
* Investment inflows seen at start of new quarter
* Coming Up: U.S. non-farm payrolls for March on Friday
(Recasts, updates prices, market activity, changes byline, dateline, previously LONDON)
By Gene Ramos
NEW YORK, April 1 (Reuters) - Oil hit a fresh 18-month high on Thursday as upbeat U.S. economic data prompted fresh fund buying at the start of the new quarter and the dollar weakened against the euro and a basket of currencies.
U.S. crude for May delivery <CLc1> climbed $1.46 to hit $85.22 a barrel, the highest intraday price since Oct. 9, 2008, before slipping back to around $85 by 12 p.m. EDT (1700 GMT). The contract had settled at $83.76 on Wednesday, its highest close since October 2008.
London ICE Brent <LCOc1> climbed $1.63 to a high of $84.33 before easing a little to trade around $84.10.
Prices were up for a fourth consecutive session as traders saw the improving outlook on economic recovery as a sign of better oil demand ahead.
The dollar shifted lower against a basket of currencies <.DXY>, a factor that usually encourages commodities buying. The dollar earlier rose against the euro. [
]Oil markets have ignored Wednesday's government report of the ninth consecutive weekly build in U.S. crude stocks, and a surprise, if small, rise in gasoline supplies. [
]"Many are looking at the fact that total implied refined product demand is now in positive territory versus both last year and the five year average for the same week," Dominick Chirichella, senior partner, Energy Management Institute in New York, said in a report.
The number of Americans filing new claims for jobless benefits fell last week and factory activity in March hit its highest level in more than 5-1/2 years, bolstering confidence of a continued expansion in the economy. [
]Crude oil futures will not trade on Friday in either New York or London because of the Easter holiday.
"Upward momentum is very strong," said Eugen Weinberg, head of commodities research at Commerzbank in Frankfurt. "The market is rising even with a stronger dollar and even after what were bearish figures on U.S. inventory levels."
"Money is flowing into commodities at the beginning of the new quarter from all sorts of investors, including funds."
U.S. government data showed U.S. crude inventories rose by 2.9 million barrels to 354.2 million barrels last week, Gasoline stocks logged an unexpected 300,000 barrel gain.
With commodities markets still closely watching economic developments, investors awaited Friday's non-farm U.S. payrolls for March, forecast to have increased in a Reuters survey.
A rise would mark only the second time payrolls have risen since the recession started in December 2007, although this might be partly on the back of hiring for the 2010 census.
"SIMMERING TENSIONS"
"We suspect that with the dollar no longer rallying, (at least for now), commodity markets have been able to build a head of steam. In addition, simmering geopolitical tensions could also be at work," said Edward Meir at brokers MF Global.
He said talk of a possible new round of sanctions against Iran, maybe within weeks rather than months, could be underpinning the market. But he added a note of caution:
"With respect to short-term pricing trends, we suspect there might be a temporary pause in the rally," Meir said.
U.S. front-month crude oil rose 5.5 percent in the first quarter, its fifth consecutive gain. But although it has more than doubled from a December 2008 low, it is still well short of a record high near $150 a barrel hit earlier that year.
After wild swings in the past two years, oil has stabilized recently near the range favored by members of the Organization of the Petroleum Exporting Countries between $70 and $80.
Last quarter, oil peaked at $83.95 a barrel in January to as low as $69.50 in February, a range of less than $15. (Additional reporting by Robert Gibbons in New York, Christopher Johnson in London; Alejandro Barbajosa in Singapore; Editing by Marguerita Choy)