New York's main contract, light sweet crude for October delivery, fell three cents to $95.27 a barrel and Brent North Sea crude for delivery in October retreated 24 cents to $113.94.
A manufacturing malaise affecting China, Europe and the US was sparking fears of a corresponding slump in crude demand, IG Markets said in a report.
"Oil was pushed down by worries of global demand and no reassurance that central banks would be able to stem the tide," the report stated.
US figures on Tuesday showed the third straight monthly contraction in the manufacturing sector after disappointing numbers from China and Europe.
The United States is the world's largest oil consumer while China is the global leader in energy consumption.
Attention is now focused on a European Central Bank meeting on Thursday, and whether any fresh stimulus measures will be announced by president Mario Draghi to kickstart economic recovery in the troubled region.
But IG Markets warned that "there are growing fears that the level of detail to be released will fall short of market expectations."