NEW YORK (Reuters) - World stocks rose 1 percent and the dollar fell yesterday as Federal Reserve Chairman Ben Bernanke left the door open for future US economic stimulus.Speaking at the Fed's annual retreat in Jackson Hole, Wyoming, Bernanke did not offer new measures to boost the economy but said it was critical for the economy's health to reduce long-term joblessness.US stocks ended more than 1 percent higher, reversing losses of as much as 2 percent just after Bernanke started speaking, while Treasuries, whose yields are at near-historic lows, ended higher but well off earlier gains.Bernanke said the central bank's policy panel would meet for two days in September instead of one to discuss additional monetary stimulus, offering some hope to investors."He didn't give the market the green light for QE3 - he also didn't give the market the red light for QE3," said Kevin Caron, market strategist at Stifel, Nicolaus in Florham Park, New Jersey, referring to the Fed's quantitative easing program."By implying that inflation is viewed as not a concern, it leaves the possibility for something down the road," he added.The speech follows several turbulent weeks for markets, with investors facing concerns about another US recession and escalating euro zone debt troubles, as well as a downgrade of the top-tier US credit rating.Analysts said the very choppy trade in many markets after Bernanke spoke reflected the concern about the US economy, as well as a realisation that US interest rates will stay at record lows for years to come.World stocks as measured by the MSCI world equity index were up 0.7 percent, but are down 11.1 percent since the start of the month, while ICE Brent for October delivery settled at $111.36 a barrel, gaining 74 cents.Bernanke's speech last year laid the groundwork for the Fed's $600 billion bond-buying program to revive the economy under the rubric "QE2" for the Fed's second round of stimulus, or quantitative easing.The stimulus plan was the basis for a sharp rally in stocks last fall.The dollar gained on the euro after the speech but later shed those gains, with the euro last up 0.8 percent at $1.4489, near a session peak of $1.4502 set on trading platform EBS.