Stock index futures extended losses on Wednesday after key U.S. retail sales data came in worse than expected, dampening hopes that consumer sentiment is recovering.

S&P 500 futures fell 16.70 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 140 points, and Nasdaq 100 futures were off 20.50 points.

(Reporting by Edward Krudy; editing by Jeffrey Benkoe)