Stocks opened lower on Monday on continued worries about euro zone sovereign debt, while Home Depot Inc helped limit losses after a brokerage upgrade.

The Dow Jones industrial average <.DJI> lost 35.89 points, or 0.36 percent, to 9,976.34. The Standard & Poor's 500 Index <.SPX> fell 2.34 points, or 0.22 percent, to 1,063.85. The Nasdaq Composite Index <.IXIC> dropped 4.36 points, or 0.20 percent, to 2,136.76.

(Editing by Jeffrey Benkoe)