U.S. February light crude was down 3 cents at $64.18 a barrel. On Friday, prices hit a session peak of $64.45 a barrel, their highest since Oct. 12. London Brent crude was up 3 cents at $62.75 a barrel. Oil prices have zoomed more than $6 higher since the last week of 2005, led primarily by a buying spree in the commodities market where two years of stellar returns as well as a weakening U.S. dollar have whetted investors' appetites. "As the U.S. dollar enters into secular decline, investors will be looking at portfolio hedges with real assests like oil and gold," said Michael Coleman, managing director of Singapore's Aisling Analytics, a hedge fund manager. The dollar touched its lowest level against the yen in about three months on Monday, hit by expectations that U.S. interest rates will not rise much further. A lack of spare refinery capacity, strong global demand growth and geo-political uncertainties also continue to keep the rally running, analysts said. Oil prices have risen 12 percent in three weeks, but are still below their Aug. 30 record $70.85. "The unfolding situation with Ariel Sharon's health... and worries over what impact Iran's nuclear ambitions will have on relations with the U.S. are weighing on where oil prices are at the moment," said Gerard Burg, minerals and energy economist with National Australia Bank. Sharon, who has been battling for his life after suffering a stroke last Wednesday, remains in a medically induced coma. Death or incapacity of Sharon, who raised peace hopes by pulling out of Gaza in September to end 38 years of military rule, would create a void in Israeli politics and efforts to forge peace with the Palestinians, analysts said. Dealers also kept an eye on Iran, with Tehran's decision to remove U.N. seals at some atomic and development sites on Monday feared likely to endanger diplomatic efforts to resolve the row, possibly leading to sanctions on OPEC's second-biggest producer. Concerns over refiners' ability to supply cleaner-burning summer gasoline, as required by the U.S. government from May, is providing additional support. U.S. gasoline inventories remain about 6 percent below year-ago levels after output was disrupted by hurricanes. They may be stretched further by the phase-out of fuel additive methyl tertiary butyl ether, especially with refiners set for a heavy spring refinery maintenance schedule. February gasoline -- trading an an unusual wintertime premium to heating fuel -- was down 0.56 percent at $1.8054 a gallon after rising 1.6 percent on Friday, while heating oil eased 0.47 percent to $1.7921 a gallon. PIN/REUTERS