Internationally traded Brent futures were at $44.77 a barrel, up 16 cents.
"There is a real risk that we could see lower prices," said Ric Spooner, chief market analyst at Sydney's CMC Markets. "The prospects for demand-growth are not large enough to go into the supply overhang."
China's economy showed renewed signs of weakness, with its manufacturing falling to a three-year low, an official survey showed on Tuesday. Although Japan's manufacturing accelerated, it was at low levels.[S7N0Z802A]
In physical markets, Dubai crude fell to the lowest since December 2008, averaging $41.691 per barrel for November, according to price-reporting agency Platts.
OPEC's policy meeting on Friday is not expected to change the organization's strategy, adopted last year, of pumping oil vigorously to protect its market share against U.S. shale drillers and other producers.
ANZ said on Tuesday it expected to see Saudi Arabia, OPEC's biggest producer, keep oil production steady in the face of declining prices.
WTI crude could fall through $40 per barrel in coming weeks if crude oil stocks do not decline in line with seasonal patterns, the bank said.
Financial traders are acting accordingly, with hedge funds' bullish wagers on U.S. crude falling to a more than five-year low amid concerns that a drop in U.S. oil output was not enough to offset a global supply glut.
U.S. government data showed no meaningful decline in shale output despite falling rig counts, adding to a glut that is seeing 0.7-2.5 million barrels per day produced beyond demand.
Oil traders are closely watching a European Central Bank policy meeting this Thursday.
"If we saw selling of the dollar and buying of the euro, it could support the oil prices and give us a bit of a rally," said CMC Markets' Spooner.
A weaker dollar is a positive for oil prices as it makes greenback-denominated contracts cheaper for those holding other currencies.
The dollar dipped slightly on Tuesday after nearing a 13-year high against a basket of currencies.
"It's really a bit of an ECB wild card at the moment," Spooner said.
(Reporting by Swetha Gopinath and Henning Gloystein; Editing by Richard Pullin and Joseph Radford)