Stocks hit session highs in late-morning trading on Thursday after sources said euro zone central banks agreed on a Greek bond swap as part of a deal to help the debt-laden nation.

The Dow Jones industrial average <.DJI> rose 85.48 points, or 0.67 percent, to 12,866.43. The S&P 500 Index <.INX> added 7.82 points, or 0.58 percent, to 1,351.05. The Nasdaq Composite <.IXIC> gained 15.28 points, or 0.52 percent, to 2,931.11.

The euro turned positive against the U.S. dollar, further supporting equities.