U.S. stocks slid further on Thursday, sending the Nasdaq index down more than 2 percent, as the appetite for riskier assets ebbed and materials and technology shares slumped.

* The benchmark S&P 500 broke below the key support level of 1,085, extending its slide from its recent 15-month closing high to 6.2 percent.

* Weaker-than-expected data on durable goods and initial jobless claims also fueled uncertainty about the economy's recovery.

* The Dow Jones industrial average <.DJI> was down 164.30 points, or 1.61 percent, at 10,071.86. The Standard & Poor's 500 Index <.SPX> was down 17.93 points, or 1.63 percent, at 1,079.57. The Nasdaq Composite Index <.IXIC> was down 52.79 points, or 2.38 percent, at 2,168.62.

(Reporting by Ellis Mnyandu; Editing by Padraic Cassidy)