U.S. stocks rose slightly at the open on Tuesday as better-than-expected home sales data for July provided further evidence that the domestic housing market was bottoming out.

* The S&P/Case-Shiller 20-city U.S. home price index for July rose 1.6 percent, higher than a 0.5 percent increase expected from economists surveyed by Reuters.

* The Dow Jones industrial average <.DJI> gained 3.18 points, or 0.03 percent, to 9,792.54. The Standard & Poor's 500 Index <.SPX> rose 1.30 points, or 0.12 percent, to 1,064.28. The Nasdaq Composite Index <.IXIC> added 0.21 points, or 0.01 percent, to 2,130.95.

(Reporting by Chuck Mikolajczak; Editing by Padraic Cassidy)