Stock index futures extended losses on Wednesday as investors waited for key retail sales data for an indication of the mood of the U.S. consumer.

S&P 500 futures fell 6.9 points 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 shed 48 points, and Nasdaq 100 futures were off 15 points.

(Reporting by Edward Krudy; editing by Jeffrey Benkoe)