US stock futures mildly lower as Amazon disappoints

U.S. stock-index futures fell Friday, paring weekly gains, amid disappointing earnings from Amazon and after the first confirmed case of Ebola in New York City prompted worries about the potential spread of the virus.

Amazon dropped sharply in early New York trading after the online retailer offered a weak sales outlook for the important holiday quarter and third-quarter results came in below estimates.

Microsoft rose after the software titan posting better-than-expected quarterly revenue; Procter & Gamble climbed after the household products maker reported quarterly results and said it would split its Duracell battery business into a separate company.

The U.S. dollar edged lower against other global currencies and the yield on the 10-year Treasury note declined 4 basis points to 2.236 percent.

Asian equities were mixed after official data released by China Friday showed new home prices falling 1.3 percent on year in September, the first annual drop in nearly two years. In Europe, meanwhile, markets traded lower on the Ebola news.

Concern about Ebola persisted, with a doctor who worked with Ebola patients in West Africa in an isolation unit in New York City on Friday after testing positive for the virus, making him the fourth person to be diagnosed with Ebola in the United States and the first in the nation's biggest city.

On the data front, new home sales for September are due at 10 a.m. ET.