NEW YORK (MarketWatch) — The S&P 500 eked out a small gain Tuesday to close at a record level for the second time this year, after reports emerged that Greece may ask for a six-month extension on its debt obligations. The benchmark index closed with gains for the third straight session. The Dow Jones Industrial Average DJIA, +0.16% ended less than 10 points from its all-time record close, adding 28.23 points, or 0.2%, to 18,047.58. The S&P 500 SPX, +0.16% added 3.35 points, or 0.2%, to 2,100.34. The Nasdaq Composite COMP, +0.11% finished the day up 5.43 points, or 0.1%, to 4,899.27.