Wall Street edges lower at open on China, tech

U.S. stocks opened slightly lower on Tuesday after China, a main source of global growth, raised interest rates, while Apple shares fell after the stock's weighting in a widely followed index was cut.

Apple Inc lost 1 percent to $337.65, but other tech giants, including Microsoft Corp and Cisco Systems , rose.

The Dow Jones industrial average <.DJI> was down 21.57 points, or 0.17 percent, at 12,378.46. The Standard & Poor's 500 Index <.SPX> was down 2.43 points, or 0.18 percent, at 1,330.44. The Nasdaq Composite Index <.IXIC> was down 0.57 points, or 0.02 percent, at 2,788.62.

(Reporting by Ryan Vlastelica; Editing by Kenneth Barry)