Benchmark crude for November delivery was down 9 cents at $84.14 a barrel at midday Singapore time in electronic trading on the New York Mercantile Exchange. The contract fell $1.34 to settle at $84.23 in New York on Thursday.
Brent crude was down 5 cents at $111.06 a barrel on the ICE Futures Exchange in London.
Crude has wandered most of this week in the mid-$80s after jumping from $75 last week amid investor optimism Europe will soon unveil a plan to contain its debt crisis. Traders will be closely watching the latest data about US retail sales, consumer sentiment and business inventories scheduled to be released later Friday for clues about crude demand.
Energy consultant Ritterbusch and Associates said in a report that developments in the European debt crisis will be the key factor driving oil prices.
News this week has been mostly negative for the oil market. On Thursday, the US Energy Department said that oil and natural gas supplies grew unexpectedly last week, suggesting demand remains sluggish. Earlier this week the International Energy Agency, the Organization of Petroleum Exporting Countries and the US Energy Information Administration all dropped forecasts for oil demand in 2012, assuming a slowdown in global economic growth.
In other Nymex trading, heating oil fell 0.1 cent at $2.97 per gallon and gasoline futures gained 0.2 cent to $2.70 per gallon. Natural gas added 0.7 cents to $3.54 per 1,000 cubic feet.
