Oil prices edged further down below $99 Tuesday, Dec 24, after gaining more than $2 last week on signs of improvement in the U.S. economy, the Associated Press reports.

Benchmark U.S. oil for February delivery was down 20 cents to $98.71 a barrel in electronic trading on the New York Mercantile Exchange.

Last week, oil rose nearly 3 percent after positive economic news that the U.S. economy had accelerated to 4.1 percent growth in the third quarter raised expections of increased demand.

Additional worry over strife in South Sudan that has seen oil workers killed and companies pulling out employees also had some analysts predicting the contract would top $100 a barrel for the first time since mid-October. However, the contract has been slipping since Monday as traders apparently deemed the fears had pushed prices too high.

Brent crude, a benchmark for international oils, continued to rise, up 2 cents at $111.58 a barrel on the ICE exchange in London.