Stock index futures added to their gains on Friday, with Dow futures turning positive as data showed durable goods orders rose more than expected in May.

S&P 500 futures rose 2.1 points and were above 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 added 12 points and Nasdaq 100 futures rose 8.25 points.

Futures had been pressured earlier after trading in some Italian banks was briefly suspended, raising new fears about the European debt crisis.

(Reporting by Ryan Vlastelica)