* Draghi holds rates steady but seems open to more stimulus
* Yellen reiterates supportive Federal Reserve view
* Separatists ignore Putin calls to postpone Ukraine secession vote
* China exports, imports beat forecast
(Updates to open of U.S. trading; changes dateline; previous LONDON)
NEW YORK, May 8 (Reuters) - Stock markets around the world jumped on Thursday, lifted by supportive comments from central banks in both Europe and the United States.
European shares climbed 1 percent after European Central Bank President Mario Draghi was seen as opening the door to more stimulus measures in June.
The ECB also resisted calls to cut rates, pushing the euro down 0.3 percent against the dollar. It previously rose to its highest level since November 2011.
In the United States, Federal Reserve Chair Janet Yellen, in speaking to the Senate Budget Committee, repeated a statement she made on Wednesday that she expects improved year-over-year growth, though weakness in the housing sector could undermine that forecast. Her comments that were seen as indicating continued support for the economy.
"Given the need to stimulate the economy, the European Central Bank may take some pages out of the U.S. play-book and become more aggressive, which should continue to lift European shares or companies tied to Europe," said Eric Teal, chief investment officer at First Citizens Bancshares Inc. in Raleigh, North Carolina.
"So long as the Fed continues to take a wait-and-see approach for removing stimulus, that should provide a good backdrop for investments."
The Dow Jones industrial average was up 67.63 points, or 0.41 percent, at 16,586.17. The Standard & Poor's 500 Index was up 7.99 points, or 0.43 percent, at 1,886.20. The Nasdaq Composite Index was up 35.91 points, or 0.88 percent, at 4,103.58.
The MSCI International ACWI Price Index rose 0.5 percent.
The yen rose slightly against the dollar while the 10-year U.S. Treasury yield was up 10/32, the yield at 2.5856 percent.
The tense situation in the Ukraine also remained in view after pro-Russian separatists in eastern Ukraine ignored a public call by Russian President Vladimir Putin to postpone a referendum on self-rule, declaring they would go ahead on Sunday with a vote that could lead to war.
Gold, viewed as a safe-haven asset, was flat on the day after dropping more than 1.5 percent over the previous two sessions. Copper was also flat.
In Asia, China's exports and imports returned to slight growth in April after a surprise fall last month, offering signs that Beijing's use of targeted policy measures to underpin growth may be starting to stabilize the economy.
U.S. crude futures fell 0.6 percent and Brent crude was off 0.3 percent. Traders continued to watch the situation in Ukraine, as well as Chinese crude imports, which jumped to a record high.
(Editing by Dan Grebler)