Stock index futures rose on Tuesday and were set to extend Monday's rebound from the past week's losses after General Motors reported higher-than-expected results and reached an agreement with the United Auto Workers union.

S&P 500 futures rose 6.20 points, above fair value, a mathematical formula that evaluates pricing by taking into account interest rates, dividends and time to expiration on the contract.

Dow Jones industrial average futures rose 57 points. Nasdaq 100 futures rose 7.75 points.

(Reporting by Kristina Cooke; Editing by Kenneth Barry)

General motors