Crude prices climbed in Asian trade Thursday as a weaker greenback and strong Chinese crude imports data buoyed markets, analysts said.
New York's main contract, light sweet crude for November delivery, gained 89 cents to 83.90 dollars a barrel in the afternoon.
Brent North Sea crude for delivery in November advanced 63 cents to 85.27 dollars on its last trading day.
A slumping US dollar was fuelling recent rallies in crude prices, said Jason Feer, Asia-Pacific vice-president and general manager of Argus Media energy market analysts in Singapore.
"The dollar's been falling," he said. "I think lately that's pretty much been the reason."
The euro was trading at 1.4086 dollars against the US dollar in afternoon trade Thursday, up from 1.3958 dollars in New York Wednesday.
Strong Chinese crude imports also lent impetus to the markets, said Commerzbank analyst Carsten Fritsch.
"China imported a record volume of crude oil of 5.67 million barrels a day in September, a year-on-year rise of 35 percent," he said, describing the figures as "more robust."
OPEC is expected to maintain official oil production quotas at its ministerial meeting in Vienna on Thursday but Feer said this would have little impact on prices as it was already widely anticipated in the markets.