The Dow Jones Industrial Average of blue-chip stocks was down 124.87 points (1.00 percent) at 12,387.17 in closing trade.

The broader S&P 500-stock index tumbled 15.26 points (1.14 percent) to 1,318.01, while the tech-heavy Nasdaq Composite fell 43.51 points (1.55 percent) to 2,759.81.

Stocks sank on opening and recovered only somewhat by the end of the session, with all but two of the 30 Dow components ending in the red.

S&P's downgrade of Italian sovereign debt fed fears of a spreading eurozone crisis, while slowing Chinese manufacturing figures were a new sign of a slowdown in the world's number-two economy. China is the biggest consumer of energy.

Copyright AFP (Agence France-Presse), 2011