U.S. stock index futures indicated a lower open on Friday with traders cautious about next week's meeting of the U.S. Federal Reserve and wary of any attempts by the market to rally.
The Fed will meet on September 16 and 17, with the timing of the U.S. central bank's first rate hike in nine years a continued source of debate in the markets.
In Europe, the pan-European STOXX 600 index was down about 1 percent, with investors also looking to next week's decision. In Asia, the Shanghai Composite Index closed 0.08 percent higher, while the Nikkei was down 0.19 percent.
Futures extended losses slightly after the Producer Price Index (PPI) for August came in unchanged, mildly beating expectations for a 0.1 percent decline. The core PPI was up 0.7 percent in the 12 months through August.
The only other major economic data due is consumer sentiment, scheduled for release at 10 a.m.
Treasury yields held slightly lower, with the 10-year yield at 2.19 percent and the 2-year yield at 0.73 percent.
Oil fell after Goldman Sachs became the latest bank to cut price forecasts. Brent crude fell more than 2 percent to near $47.80 a barrel and WTI crude fell 2.3 percent to near $44.90 a barrel.
On the earnings front, Mattress Firm missed estimates by 5 cents with adjusted quarterly profit of 67 cents per share, with revenue also missing forecasts.
Kroger reported second-quarter earnings of 44 cents a share on revenue of $25.54 billion, for a 25 percent increase in profit from the same period last year.
--CNBC's Patti Domm and Peter Schacknow contributed to this report.