The US government is expected to release figures on jobless claims and inflation in the world's biggest economy, which is struggling to avoid dipping back into recession.
A stronger US dollar also helped push prices lower as it makes the dollar-priced commodity more expensive for buyers using other currencies, dampening demand, analysts said.
New York's main contract, West Texas Intermediate light sweet crude for September delivery, was down 33 cents to USD 87.25 a barrel in Asian morning trade. Brent North Sea crude for October fell 30 cents to USD 110.30.
"Jobs are where the angst resides, the inflation call is more benign, though not completely," DBS Bank said in a market commentary on the US economy.
"Poor sentiment of the past two weeks is bound to feed into some of the hard data and the fact is that labour/jobs data are the most prone of all to sentiment," it said.
"Another fact is that jobs data make for the biggest headlines and nobody wants to see more sand thrown into the wind just now. So if we can get through this week and next week without a surge in jobless claims, then the outlook for Q3 has just gone up by an order of magnitude."
Investors are closely watching the health of US economy amid fears it could sink into another recession because it consumes more oil than any other country in the world.
Victor Shum, an analyst with Purvin and Gertz energy consultancy in Singapore, said oil prices were also edging down "in parallel with the strengthening of the US dollar against the euro".