* European shares, bonds rebound for second day * U.S. 1st-quarter final growth estimate cut to 1.8 pct * Dovish comments from ECB's Draghi weigh on euro * Oil prices slide, bond prices gain * Gold hits an almost 3-year low By Herbert Lash NEW YORK, June 26 (Reuters) - The dollar rose and global equity markets gained for a second day on Wednesday after a surprisingly sharp downward revision to first-quarter U.S. economic growth eased concerns that the Federal Reserve may soon begin to withdraw stimulus. In addition, moves by China to calm bank fears and supportive signs from the European Central Bank on the need for continued stimulus helped extend Tuesday's rebound after the global sell-off last week of stocks, commodities and bonds. U.S. gross domestic product grew at only a 1.8 percent annual rate in the first quarter, the Commerce Department said in its final estimate, down from the prior estimate of a 2.4 percent pace. The benchmark S&P 500 stock index was on track for its biggest two-day gain in three weeks, cutting the decline since its all-time closing high on May 21 to 3.9 percent. "Despite all the rhetoric and fear about tapering, this will keep the Fed firmly planted in stimulus, which is a positive for the market," said Michael Mullaney, chief investment officer at Fiduciary Trust Co in Boston, which oversees about $9.5 billion. "This is another example of bad news being good news," he said. European stocks gained close to 2 percent to post their biggest two-day gain since April after the ECB's president, Mario Draghi, said an accommodative monetary policy was still appropriate. The bank's policy, he said, "will stay accommodative for the foreseeable future." MSCI's all-country world equity index rose 0.95 percent, while the pan-European FTSEurofirst 300 index of leading regional companies gained 1.71 percent to close at 1,149.71 points. The EuroSTOXX 50 index rose 2.34 percent. The Dow Jones industrial average was up 146.60 points, or 0.99 percent, at 14,906.91. The Standard & Poor's 500 Index was up 15.49 points, or 0.98 percent, at 1,603.52. The Nasdaq Composite Index was up 29.16 points, or 0.87 percent, at 3,377.05. The S&P 500's advance followed a gain of nearly 1 percent on Tuesday, spurred after U.S. data on durable goods orders, sales of new homes and consumer confidence all topped expectations. A pledge by China's central bank, the People's Bank of China, to act as a lender of last resort was the story of the day on Wednesday, said Fred Dickson, chief market strategist at The Davidson Cos. in Lake Oswego, Oregon. "The global fears regarding the possibility of a Chinese credit situation spilling over and becoming very serious has eased off some," he said. The People's Bank "is going to come in and make sure the Chinese banking system doesn't collapse." Gold hit its lowest level in almost three years and was on course for a record quarterly loss. Prices could slide to levels below $1,000 per ounce, investors and analysts said. Spot gold prices fell $46.40 to $1,230.30 an ounce. Bond markets in Europe and benchmark U.S. Treasuries continued to claw back ground, although investors remained worried that the rebound could give way with markets likely to need more time to acclimatize to the new environment. U.S. Treasuries gained after a recent slump took yields to near two-year highs, with the weaker-than-expected GDP pointing to continued potential for fragility in the world's biggest economy. The benchmark 10-year U.S. Treasury note was up 11/32 in price to yield 2.569 percent. Euro zone bonds rose across the board on the ECB's pledge to keep exceptional monetary policy measures for the foreseeable future. German Bund futures came off 8-month lows on Monday of 139.90 to settle up 49 ticks at 141.03. If economic data is weak, "the punch bowl stays where it is. Good news, economically, the punch bowl gets moved a little bit further away," said Wilmer Stith, co-manager of the Wilmington Broad Market Bond Fund in Baltimore. Oil prices traded near break-even after data showed an unexpected rise in U.S. crude stocks, which combined with the GDP report, stoked concerns about the outlook for demand in the world's top consumer. Brent crude for August delivery 7 cents at $101.33 a barrel. U.S. crude settled up 18 cents at $95.50 a barrel. The euro was down 0.64 percent at $1.3000, stung by Draghi's comments on an accommodative monetary policy and the risks to growth in the euro zone. "Juxtaposed against shifting Fed policy, (Draghi's comment) highlights that relative central bank policy will soon shift from supporting to weighing on the euro," Camilla Sutton, chief FX strategist at Scotiabank, said. The dollar rose to a three-week high of 83.003 against a basket of currencies, buoyed mainly by solid gains against the euro. It later traded at 82.979.