Stocks extended losses on Monday as data showing a decline in European private sector activity last month and a reduced target for China growth renewed concerns about the global economy, while a drop in Apple shares hit the Nasdaq.

Trading in Apple was erratic. The stock hit an intraday low of $526, down 3.5 percent, before easing to $536.50. The shares are up 33 percent since late December.

The Dow Jones industrial average <.DJI> dropped 73.03 points, or 0.56 percent, to 12,904.54. The Standard & Poor's 500 Index <.SPX> dropped 9.15 points, or 0.67 percent, to 1,360.48. The Nasdaq Composite Index <.IXIC> dropped 28.31 points, or 0.95 percent, to 2,947.88.

(Reporting By Edward Krudy)