* Wall Street gains for 4th day on ECB move, Greek support
* Rally in European equities, short covering support Brent
* Investors sell safe-haven U.S. debt for riskier assets
* Euro jumps on ECB dollar funding, Greek support (Adds opening of U.S. markets, byline, dateline; previous LONDON)
By Herbert Lash
NEW YORK, Sept 15 (Reuters) - Global stocks advanced for a third straight day and the euro gained on Thursday after major central banks moved to boost European bank funding and strong support for Greece by regional leaders eased default fears.
European shares extended gains to more than 2 percent and the euro jumped more than 1 percent after the European Central Bank said it would boost the short-term supply of dollars in a move to ease funding difficulties in the euro zone. For details see: [ID:nF9E7JT00G]
The euro
The FTSEurofirst 300 <.FTEU3> index of top European shares rose 2.7 percent. The benchmark index has gained 6 percent since touching a two-year low on Tuesday.
Peter Boockvar, equity strategist at Miller Tabak + Co in New York, said the move by the ECB and other major central banks was "a positive in that short term relief is being given but a negative that we are at this state to begin with."
"The stress is still there as long as sovereign debt issues aren't dealt with aggressively but this move eases short term funding problems," Boockvar said.
On Wall Street, the Dow Jones industrial average <.DJI> was up 147.17 points, or 1.31 percent, at 11,393.90. The Standard & Poor's 500 Index <.SPX> was up 14.84 points, or 1.25 percent, at 1,203.52. The Nasdaq Composite Index <.IXIC> was up 26.35 points, or 1.02 percent, at 2,598.90.
Widespread optimism came even as German Chancellor Angela Merkel bluntly rejected the notion of euro zone bonds -- a focal point for market optimism on Wednesday -- as a solution to Europe's sovereign debt crisis. [ID:nL5E7KF1CX]
There was also no clear sign from a conference call of German, French and Greek leaders on Wednesday that a stalemate over Athens' next bailout payment had been broken. [ID:nLDE78D090]
Investors also pushed aside a fresh spate of disappointing U.S. data that showed new U.S. jobless claims rose last week to their highest since June and a gauge of factory activity in New York state contracted in September. [ID:nS1E78E0CT]
The news supported the view the Federal Reserve could take new action to boost economic growth.
"The overall picture from the three data releases we are looking at is not very good," said Sean Incremona, an economist at 4Cast Ltd in New York.
Another survey showed that a gauge of factory activity in the U.S. Mid-Atlantic region contracted for a second month in a row in September, but the rate of decline moderated from a steep drop the month before.
The price of the 30-year U.S. Treasury bond fell more than a full point as the prospect of a long stretch of loose monetary policy coupled with higher inflation prompted investors to dump long bonds.
The 30-year bond
Bund futures fell as euro zone leaders showed signs of their determination to see out Greece's debt problems without it leaving the single currency, prompting some to take profit on a recent rally in safe-haven bonds. [ID:nL5E7KF192]
Crude oil rose more than $3 a barrel, buoyed by the rally in European equities, a weaker dollar and improved risk appetite after euro zone leaders reiterated their commitment to keeping Greece afloat. [ID:nL3E7KF0IJ]
Brent crude