U.S. stock index futures extended losses on Wednesday despite data showing U.S. private employers added 32,000 jobs in April, slightly more than expected.

S&P 500 futures fell 5.8 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 lost 50 points and Nasdaq 100 futures fell 9 points.

Futures were trading lower as investors continued to eye the Greek sovereign debt crisis and its potential to spread.

(Reporting by Rodrigo Campos; Editing by Padraic Cassidy)