U.S. stocks open lower ahead of next week' s Fed meeting

U.S. stocks opened lower on Friday, as cautious traders were waiting for a decision on rate hike by the U.S. Federal Reserve next week.

Wall Street remains focused on the Fed ahead of its key policy meeting on Sept. 16-17, when the central bank could raise interest rates for the first time in more than nine years.

Analysts said uncertainty about the Fed's rate decision at its two-day policy meeting has contributed to the recent market volatility.

The strengthening U.S. labor market and falling import prices, however, triggered market debate over whether the policymakers should raise interest rates next week.

On the economic front, the Producer Price Index for final demand was unchanged in August, seasonally adjusted, beating market expectations for a 0.1 percent decline, the U.S. Labor Department said Friday.

Investors will also keep a close eye on the University of Michigan's preliminary September reading of consumer sentiment index due later Friday.

Shortly after the opening bell, the Dow Jones Industrial Average lost 56.02 points, or 0.34 percent, to 16,274.38. The S&P 500 fell 7.36 points, or 0.38 percent, to 1,944.93. The Nasdaq Composite Index was down 20.76 points, or 0.43 percent, to 4,775.49.

U.S. stocks posted sizable gains after volatile trading Thursday, as investors tried to digest mixed economic reports ahead of the Federal Reserve's policy meeting next week. Endite