Aug 7 (Reuters) - U.S. stock index futures extended gains on Friday after data showed the U.S. economy unexpectedly shed jobs in July, dampening expectations of an interest-rate hike in September.

A Labor Department report showed nonfarm payrolls fell 23,000 in the month before, far below the 80,000 job additions that economists polled by Reuters were expecting.

Unemployment stood at 4.1% in July, easing from 4.2% in June. Average earnings on an annual basis rose 3.2% in July, compared with the 3.5% economists were expecting.

At 9:33 a.m. ET, U.S. S&P 500 E-minis were up 26 points, or 0.34%, Nasdaq 100 E-minis were up 225.5 points, or 0.76%, Dow E-minis were up 97 points, or 0.18%.