Wall Street pares gains, Nasdaq turns negative

NEW YORK (Reuters) - U.S. stocks pared early gains and the Nasdaq turned negative on Wednesday as investors continued to mull how soon central banks will begin to scale back supportive measures.

The Dow Jones industrial average gained 9.21 points, or 0.06 percent, to 15,131.23. The Standard & Poor's 500 Index added 1.24 points, or 0.08 percent, to 1,627.37. The Nasdaq Composite Index lost 2.65 points, or 0.08 percent, to 3,434.30.

(Reporting by Chuck Mikolajczak; Editing by Nick Zieminski)