The price of oil inched up above $99 a barrel Tuesday as hopes over the U.S. economy continued to drive up expectations over the country's demand for energy.

By early afternoon in Europe, benchmark U.S. oil for February delivery was up 27 cents to $99.18 a barrel in electronic trading on the New York Mercantile Exchange. On Monday, the Nymex contract fell 41 cents to close at $98.91 a barrel.

Oil prices rose nearly 3 percent last week and are up around 7 percent so far in December. Hopes over the U.S. economy have lain behind the rise — last week figures showed that the U.S. economy grew at an annualized rate of 4.1 percent growth in the third quarter, ahead of previous expectations.

Additional worries over violence and instability in South Sudan have led some analysts to predict the contract may top $100 a barrel for the first time since mid-October.

"Tensions in the still young country of South Sudan are rising further," analysts at JBC Energy in Vienna said in a note. "As the year comes to a close, the risk of an all-out civil war that could stymie the country's production of around 250,000 barrels a day is growing."

Traders are also on the lookout for news on U.S. stockpiles of crude and refined products.

Data for the week ending Dec. 20 are expected to show a draw of 2.3 million barrels in crude oil stocks and a build of 2.2 million barrels in gasoline stocks, according to a survey of analysts by Platts, the energy information arm of McGraw-Hill Cos.

The American Petroleum Institute will release its report on oil stocks later Tuesday, while the report from the Energy Department's Energy Information Administration — the market benchmark — will be out on Friday, two days later than usual because of the Christmas holiday.

Brent crude, a benchmark for international oils, was up 31 cents to $111.87 a barrel on the ICE Futures exchange in London.

In other energy futures trading on Nymex:

— Wholesale gasoline gained 0.6 cent to $2.7867 a gallon.

— Heating oil advanced 1.08 cents to $3.0042 a gallon

— Natural gas fell 0.6 cent to $4.457 per 1,000 cubic feet.