Oil prices fell on Tuesday, extending losses into a third week on worries over a supply glut and with US inventory data expected to show another increase in crude stocks.
Brent for December delivery had fallen 21 cents to $47.34 a barrel by 0434 GMT, after settling the previous session down 45 cents.
US crude for December delivery dropped 45 cents to $43.53 a barrel, having ended the day before down 62 cents.
The US benchmark broke technical support, dropping 65 cents, to hit a nine-week low earlier in the session on Tuesday.
An expected further build in US crude stocks last week again raised concerns of an oversupplied market, said Ric Spooner, chief market analyst at Sydney's CMC Markets.
US production cuts -- from a peak of around 9.6 million barrels a day to around 9.1 million -- and optimism over demand hasn't translated into higher prices, he said.
"There's minor potential support (for U.S. oil) from the early September low around $43.20 and just below that the 61.8 percent Fibonacci retracement around $42.80," he said, adding Brent had some support from previous lows between $45.98 and $46.93.
US commercial crude stockpiles likely rose for a fifth straight week, by an average of 3 million barrels to 479.6 million, in the week ended 23 October, a preliminary Reuters survey showed.
While stocks of distillates, which include diesel and jet fuel, were seen falling 2 million barrels, storage utilisation for distillates in the US and Europe is nearing historic highs, according to a Goldman Sachs report on Monday.
"Inventories ... (and) U.S. production numbers continue to disappoint the market," said Ben Le Brun, market analyst at Sydney's OptionsXpress.
Investors are also waiting for the outcomes of key policy meetings this week, Le Brun said.
That includes the outcome of a US Federal Reserve Open Market Committee policy meeting which starts later on Tuesday and China's fifth plenum, a meeting of the Communist Party's central committee, that began on Monday.
Oil prices could get support from short covering if investors think the Fed will take a dovish view towards interest rates at its meeting, Spooner said.