Wall St ends mixed

All three major averages had been sharply lower for most of the session amid concerns  over possible Greek exit from the euro zone and ahead of an informal EU summit in Brussels.
Dow Jones Industrial Average fell 6.66 points, or 0.05 percent, to close at 12,496.15.
S&P 500 added 2.23 points, or 0.17 per cent at 1,318.86.
Nasdaq rose 11.04 points, or 0.39 per cent at 2,850.12.
Among the key S&P sectors, utilities ended lower, while materials ended higher.