Wall St. falls as Chinese shares, commodities slide

Wall Street began the week in the red on Monday and fell sharply on concerns about China's slowing growth in the wake of the biggest drop in Shanghai shares in eight years.

The Dow Jones industrial average fell to its lowest level in over five months while the Nasdaq composite was at a four-week low and the S&P 500 touched its lowest in more than two weeks.

Chinese shares tumbled more than 8 percent as an unprecedented government rescue plan to prop up valuations abruptly ran out of steam, raising doubts about the viability of Beijing's efforts to stave off a deeper crash.

Commodity prices resumed their downward spiral with the broader Thomson Reuters CRB commodities index (.TRJCRB) hitting its lowest in six years and oil prices hitting a four-month low.

Chinese ADRs including Alibaba (BABA.N), Baozun (BZUN.O), Sohu.com (SOHU.O) and JD.com (JD.O) slid.

The S&P 500 and Nasdaq posted their largest weekly drops since March on Friday as slowing global growth dragged commodity-related stocks lower.

"This really has its roots in nervousness that began in the U.S. at the end of last week," said Andy Sullivan, a portfolio manager with Swiss investment firm GL Financial Group.

"Shanghai is an artificial market at the moment reliant on government support, and they have thrown the kitchen sink at it in recent weeks. The selling just ratcheted up steadily this morning."

At 9:44 a.m. EDT (1344 GMT), the Dow Jones industrial average (.DJI) was down 159.41 points, or 0.91 percent, at 17,409.12, the S&P 500 (.SPX) was down 15.54 points, or 0.75 percent, at 2,064.11 and the Nasdaq composite (.IXIC) was down 48.47 points, or 0.95 percent, at 5,040.16.

Apple's (AAPL.O) 1.3 percent fall weighed the most on the S&P and the Nasdaq while the Dow was dragged down by Goldman Sachs' (GS.N) 1.7 percent drop.