Benchmark crude for March delivery was down 29 cents at $99.55 a barrel at midday Singapore time in electronic trading on the New York Mercantile Exchange. The contract rose $1.13 to settle at $99.84 on Thursday.

Brent crude was down 50 cents at $118.09 a barrel on the ICE Futures Exchange in London.

Crude has bobbed around $100 for the last few months, buoyed by signs the U.S. economy is improving. On Thursday, the U.S. reported that the number of Americans seeking unemployment benefits fell to near a four-year low last week, suggesting the job market is gaining strength.

"The energy market appears positioned for additional price gains as we still look for crude to work its way up to the $101 area," energy consultant Ritterbusch and Associates said in a report.