* Stocks set to end week lower, eyes on FOMC next week
* Producer prices rise more than expected
* Consumer sentiment data on tap
* Groupon jumps after Deutsche Bank raises rating
* Futures down: Dow 12 pts, S&P 1.4 pts, Nasdaq 3.5 pts
By Leah Schnurr
NEW YORK, June 14 (Reuters) - Wall Street was set to open little changed on Friday, though stocks looked likely to rack up a loss for the week, as investors were kept on their heels by uncertainty over how soon central banks will rein in their stimulus programs.
Jitters over the longevity of monetary policy around the world has roiled markets recently and nerves were stretched further this week when the Bank of Japan decided to hold policy steady. The extraordinary measures taken by policymakers to support the economy have helped fuel a rally that has boosted the S&P by nearly 15 percent this year so far.
The prospect that the accommodative stance of central banks - particularly the Federal Reserve - could be pulled bank sooner than expected has prompted traders to rethink bets that were built around that support. Stocks have fallen during three of the past four days, and heading into Friday's session, the S&P 500 is down 0.4 percent on the week.
Attention is now focused on the Fed's policy-setting meeting next week. Investors will be looking for insight into how soon the central bank will wind down its monthly $85-billion bond purchase plan.
"Markets are looking at next week's Fed meeting to be the big driver in the short-term," said Kim Forrest, senior equity research analyst at Fort Pitt Capital Group in Pittsburgh.
"Bernanke has really increased the amount of transparency in the Fed's thinking," said Forrest. "This isn't going to be a jack-in-the-box surprise Fed, it's going to be a Fed that clearly indicates what it's going to do. That's why people are looking to this meeting in particular."
Economic data offered some support and futures trimmed declines after a report showed producer prices rose more than expected in May as gasoline prices rebounded, and underlying inflation pressures remained muted.
Other reports due on Friday include data on industrial production and consumer sentiment.
S&P 500 futures fell 1.4 points but were above fair value, a formula that evaluates pricing by taking into account interest rates, dividends and time to expiration on the contract. Dow Jones industrial average futures was off 12 points, and Nasdaq 100 futures lost 3.5 points.
Smith & Wesson Holding Corp's shares rose in premarket trading after the gun maker raised its outlook for the fourth quarter. The stock was up 5.5 percent at $9.81.
Groupon climbed 6.7 percent to $7.32 after Deutsche Bank raised its rating to "buy" from "hold", according to Benzinga.com.
Boeing Co is poised to launch a larger member of its 787 Dreamliner jetliner family to meet demand for long-haul travel within Asia and other long-distance routes, sources said.
Broadcast Music Inc (BMI), a songwriters' rights organization, is suing Pandora Media after the Internet radio company rejected a request to pay a higher license fee for playing songs across various devices.
Shares of Solarcity jumped 7.5 percent to $36.58 after Credit Suisse raised its rating to "outperform" from "neutral," according to Flyonthewall.com.