Stock index futures pared gains and S&P 500 futures turned negative on Monday as crude oil prices continued to rise on supply concerns due to Libya's unrest.

S&P 500 futures dipped 1 point and were below fair value, a formula that evaluates pricing by taking into account interest rates, dividends and time to expiration on the contract. Dow Jones industrial average futures gained 40 points, and Nasdaq 100 futures added 1 point.