Benchmark oil for August delivery was down 21 cents at $85.60 a barrel at midday Singapore time in electronic trading on the New York Mercantile Exchange. Crude rose $1.90 to settle at $85.81 on Wednesday in New York.
In London, Brent crude for August delivery was down 22 cents at $100.01 per barrel on the ICE Futures exchange.
Crude has plummeted from $106 in May amid expectations that a global slowdown led by Europe, the U.S. and China will undermine oil demand.
Some analysts expect crude prices to recover in the second half of the year as policymakers use fiscal and monetary stimulus to boost economic growth and fuel consumer demand. In minutes of its last meeting that were released Wednesday, the U.S. Federal Reserve did not suggest it plans to ease monetary policy soon.