(REUTERS) - Stocks rose at the open on Tuesday following an equities selloff the day before, but anxiety over Europe's debt problems kept markets jittery ahead of the Federal Reserve's assessment of the economy.

The Dow Jones industrial average gained 94.72 points, or 0.79 percent, to 12,116.11. The Standard & Poor's 500 Index rose 9.98 points, or 0.81 percent, to 1,246.45. The Nasdaq Composite Index climbed 23.67 points, or 0.91 percent, to 2,635.93.

(Reporting By Chuck Mikolajczak; editing by Jeffrey Benkoe)