Stock index futures extended losses on Monday after Intel Corp cut its fourth quarter revenue expectations.

Wall Street stocks were set to fall at the open on lingering concerns a deal over economic integration in Europe will not be enough to keep the region's two-year sovereign debt crisis from spreading further.

S&P 500 futures fell 15.7 points and were below fair value, a formula that evaluates pricing by taking into account interest rates, dividends and time to expiration of the contract. Dow Jones industrial average futures lost 119 points and Nasdaq 100 futures dropped 27 points.

(Reporting by Rodrigo Campos; Editing by Padraic Cassidy)