EILEEN AJ CONNELLYNEW YORK (AP) â¿¿ The stock market posted substantial gains Thursday as Greece closed in on a deal to restructure its debt and avoid a default. That overshadowed a small increase in unemployment claims last week. The Dow Jones industrial average closed up 70.61 points, or 0.6 percent, at 12,907.94. Two days of solid gains have erased about three-quarters of the losses from Tuesday, when the Dow fell 203 points, its biggest loss of the year. The close left the Dow up 97 percent since March 9, 2009, its low point during the Great Recession. Last week, the Dow closed above 13,000 for the first time since May 2008. The Standard & Poor's 500 index has more than doubled in three years. On Thursday, the S&P 500 added 13.28 points, or 1 percent, to 1,365.91. It has gained 22.80 points since Tuesday, its best two days since December. All 10 industry groups rose, led by materials companies. The Nasdaq composite index rose 34.73 points, or 1.2 percent, to 2,970.42. A Greek government official told The Associated Press that more than 75 percent of investors in Greek bonds had agreed to exchange them for bonds with a lower face value and interest rate. Greece needs 90 percent of investors to participate to get a bailout of â¿¬130 billion, or about $173 billion, and avoid a default later this month that could rattle financial markets around the world. The Athens government will release final results Friday. The Greek crisis is "starting to wind down, we hope," said Paul Powers, head of U.S. equity sales trading for Raymond James. "It doesn't seem nearly as dire as it was a couple of weeks ago." The rally came despite a report from the Labor Department that the number of people seeking unemployment benefits rose slightly more than expected last week. The four-week average remained near a four-year low.