* Oil prices fall after Goldman Sachs cuts forecast
* S&P poised for biggest weekly gain since July
* Zumiez falls after cutting third-qtr forecast
* Indexes down: Dow 0.19 pct, S&P 0.42 pct, Nasdaq 0.53 pct (Adds details, changes comment, updates prices)
By Tanya Agrawal
Sept 11 (Reuters) - Wall Street was lower on Friday as jittery investors took to the sidelines ahead of a crucial U.S. Federal Reserve meeting next week, when the central bank decides on an interest rate hike.
However, the S&P 500 was poised for its biggest weekly gain in six weeks despite the recent volatility that has rocked the global financial market.
Stocks have been volatile for the past few weeks since China devalued its currency in August and the impact of a slowdown in the region on global growth rattled investors. The S&P 500 has had moves of at least 1 percent in 11 sessions since Aug. 20.
Investors pulled another $15.9 billion from U.S. equities over the past week as they sought safety in government bond funds, Bank of America Merrill Lynch said.
The Fed has said it will raise rates for the first time since 2006 when it sees a sustained economic recovery with special emphasis on the job market and inflation.
Data released in the past two days has painted a mixed picture, further clouding the outlook for what the Fed will decide to do at its Sept. 16-17 policy meeting.
While weekly unemployment claims fell, producer prices for August were unchanged pointing to benign inflation pressures. Another survey showed that U.S. consumer sentiment dropped to its lowest level since September last year.
"There is a lot of uncertainty going into the weekend before the Fed meeting," said Randy Frederick, managing director of trading and derivatives for Charles Schwab in Austin, Texas.
"The volatility will remain till the Fed meeting and if it decides not to raise interest rates next week, the volatility will continue and maybe get worse for a lot longer."
Considering volatile global equities, increasing uncertainty over China and emerging markets as well as an easing of policy by other major central banks, it could be a high bar for the Fed to raise rates next week.
"Given that markets have done much of the Fed's 'dirty work', we expect Fed officials to be on hold at least until December," Goldman Sachs U.S. economists wrote in a note to clients.
At 11:08 a.m. ET (1508 GMT) the Dow Jones industrial average was down 31.77 points, or 0.19 percent, at 16,298.63, the S&P 500 was down 8.21 points, or 0.42 percent, at 1,944.08 and the Nasdaq Composite was down 25.35 points, or 0.53 percent, at 4,770.90.