Oil prices extended heavy recent losses on Wednesday as U.S. government data showed crude stocks building for an eighth straight week ahead of winter.
U.S. light crude dropped 33 cents to $45.78 a barrel, extending a fall of more than 17 percent from late-October's record high at $55.67 a barrel. London Brent crude was down 54 cents at $41.75.
Prices tumbled after the U.S. Energy Information Adminstration said crude stocks rose by 800,000 barrels to 292.3 million last week. Crude stocks have risen nearly 23 million barrels, or more than 8 percent, since late September as strong OPEC production and slowing global demand growth have helped replenish consumers' inventories.
Rising supplies have calmed traders' fears of a supply squeeze during the northern hemisphere winter and prompted speculative funds to shift money out of oil following a rally that has driven up prices 40 percent this year.
OPEC's reference crude oil basket has fallen to its lowest level since mid-July at $35.94.
Nevertheless, low stocks of heating oil in the big consuming markets of the United States, Germany, and Japan are keeping the market on edge ahead of the northern winter, dealers say. U.S distillate stocks, including heating oil and diesel fuel, fell by 1.0 million barrels to 114.6 barrels, the ninth consecutive weekly fall, the EIA said.
Analysts say an early or severe winter could stress inventories, prompting a fresh influx of buying by funds. So far, temperatures have been relatively mild, although forecasters warn of a major U.S. cold front next week.
Export flows through Iraq's northern oil pipeline have fallen to 200,000 barrels per day after a new series of sabotage attacks, and could remain below capacity for over a month.
