Crude futures dropped by more than a half a dollar a barrel Monday as electronic trade restarted on the New York Mercantile Exchange, and investors reacted to the softer prices registered by the London exchange last Friday.
Light, sweet crude for February delivery on Nymex slipped back by 77 cents to $43.41 a barrel, taking the contract's drop to close to 5.1 percent, over the past week.
"This is just a reaction to where the (London) market went on Friday," said Esa Ramasamy, oil editorial manager for energy reporting agency Platts in Singapore. The world's largest earthquake in 40 years, which hit parts of Asia on Sunday, was apparently not a factor.
Nymex did not open Friday, ahead the Christmas weekend holiday. But Brent futures traded on London's International Petroleum Exchange sagged 60 cents to $40.11 a barrel that day on expectations of milder winter weather in the United States. The IPE is closed Monday and Tuesday.
Over the past month, the energy market has zeroed in on the severity of the of Northern Hemisphere winter and the consequent strength of demand for oil products, especially heating oil, stocks of which are lower than at this time last year.
The weather and stockpiles watch come after a year when crude costs were pushed to a series of record highs, as global demand remained robust while spare production capacity was reduced to multiyear lows.
At the same time, concern flared about supply disruptions in Russia, Nigeria, Venezuela and Iraq.
Crude futures prices peaked at more than $55 a barrel in October, but have since retreated as stockpiles have risen and as U.S. weather has so far remained relatively mild.