Stocks edged lower at the open on Monday after data showing a decline in European private sector activity and a lower growth target for China gave investors reason to pause after 3 weeks of gains for the S&P 500.

The Dow Jones industrial average <.DJI> dropped 21.87 points, or 0.17 percent, to 12,955.70. The S&P 500 Index <.INX> fell 3.26 points, or 0.24 percent, to 1,366.37. The Nasdaq Composite <.IXIC> lost 6.45 points, or 0.22 percent, to 2,969.74.

(Reporting by Rodrigo Campos; editing by Jeffrey Benkoe)