* Fed chief plays down chances of further stimulus
* World stocks fall after Bernanke disappointment
* Oil prices advance after OPEC fails to lift output (Adds quote, detail, updates prices)
By Wanfeng Zhou
NEW YORK, June 8 (Reuters) - Major stock markets fell on Wednesday on worries about a bleak global economic outlook, while oil prices jumped after OPEC failed to reach an agreement to increase output.
The U.S. dollar hit a one-month low below 80 yen as risk aversion rose, but the greenback gained against the euro after weaker-than-expected German economic data and on uncertainty over a second Greek bailout package.
Federal Reserve Chairman Ben Bernanke on Tuesday acknowledged that the U.S. economy had slowed but offered no hint that the central bank is considering further stimulus to support growth.
Bernanke's comments, combined with recent weak U.S. labor and manufacturing data, stoked fears that a slowdown in the world's largest economy could dent global growth. For more, see [ID:nW1E7GV010]
"The question marks regarding the growth dynamics for the global economy are becoming bigger and this is weighing on the markets," said Tammo Greetfeld, equity strategist at UniCredit.
World stocks as measured by the MSCI world equity index <.MIWD00000PUS> slipped 0.5 percent. The Thomson Reuters global stock index <.TRXFLDGLPU> also lost 0.5 percent. Emerging market stocks <.MSCIEF> fell 0.6 percent.
The FTSEurofirst 300 <.FTEU3> index of top European shares was down 0.8 percent at 1,095.21, plumbing a two-and-a-half month low and a sixth straight day of losses.
U.S. stocks were lower in choppy trading, with gains in energy shares failing to offset bearish sentiment stemming from Bernanke's comments.
The Dow Jones industrial average <.DJI> was down 1.21 points, or 0.01 percent, at 12,069.60. The Standard & Poor's 500 Index <.SPX> was down 1.45 points, or 0.11 percent, at 1,283.49. The Nasdaq Composite Index <.IXIC> was down 14.50 points, or 0.54 percent, at 2,687.06.
Brent crude oil
OPEC talks broke down without an agreement to raise output after Saudi Arabia failed to convince other members to lift production. The news raised fears of supply shortages later this year and a price rally that could further damage a global economic recovery. [ID:nL3E7H80BY]
OPEC Secretary General Abdullah El-Badri said OPEC hoped to meet again in three months to assess the situation.
"I do not think it is a surprise, but it is a supportive factor and I think this will get us back up to $100 and pivot around there until something else happens," said Chris Dillman, an analyst at Tradition Energy in Stamford, Connecticut.
DATA, GREECE HIT EURO
The dollar was last down 0.3 percent at 79.88 yen
The euro
German exports posted their biggest drop in more than two years in April and industry output fell 0.6 percent, confounding expectations for an unchanged reading, data showed on Wednesday. For more, see [ID:nLDE7570B7] [ID:nLDE75706Q]
Greece needs substantial fresh aid from the euro zone to avoid the currency bloc's first state insolvency, a German newspaper reported on Tuesday, citing German Finance Minister Wolfgang Schaeuble. [ID:nB4E7G900O]
The cost of insuring Greek and Portuguese debt against default rose, while the premium investors demand to hold Greek, Portuguese and Irish government bonds rather than benchmark German Bunds also increased.
German government Bunds rose around 13 ticks
U.S. benchmark Treasury yields fell back below the key 3 percent level as worries over the tepid pace of economic growth spurred investors to buy into lower-risk assets.
Yields on 10-year notes