"Oil continues to call the shots for the equity market and has left economics news secondary in investors' minds," said Scott Marcouiller at Wells Fargo Advisors.

"The persistent advance in oil prices is keeping sentiment in check, and markets are well off of the best levels of the morning," said Charles Schwab analysts in and early note.

At 15:15 the Dow Jones Industrial Average was up 33.04 points (0.27 percent) to 12,202.92.

The S&P 500 index, a broader measure of the markets, added 2.44 points (0.18 percent) at 1,323.59, while the tech-rich Nasdaq Composite lost 3.78 points (0.14 percent) to 2,780.89.

Exxon shares rose 1.1 percent, Chevron 1.0 percent, and Petrobras' New York shares jumped 2.1 percent as world oil prices spiked to fresh 30 month highs on the deepening conflict in Libya.

New York's main futures contract, light sweet crude for delivery in April, topped $106 a barrel in opening trade after gaining more than 20 percent over the past two weeks.

Shares of hard disc drive maker Western Digital soared 17.8 percent after it said it was buying a unit of Japan's Hitachi Ltd., Hitachi Global Storage Technologies.

On Friday, soaring oil prices outweighed positive US jobs data showing the economy added 192,000 jobs in February and the unemployment rate fell to 8.9 percent from 9.0 percent.

Bond prices fell. The yield on the 10 year Treasury moved up to 3.54 percent from 3.49 percent late Friday, while the 30 year bond rose to 4.65 percent from 4.60 percent.