US STOCKS-Wall St sells off, S&P 500 at 11-1/2 yr low

(Updates to 4 p.m.)

NEW YORK, Nov 20 (Reuters) - U.S. stocks plunged yet again on Thursday, as a frantic flight from risk on investors' deepening economic fears left the benchmark Standard & Poor's 500 index at its lowest level since 1997 -- completing the erasure of more than a decade of stock market gains.

The Dow Jones industrial average .DJI slid 444.99 points, or 5.56 percent, to close unofficially at 7,552.29. The Standard & Poor's 500 Index .SPX plunged 54.14 points, or 6.71 percent, to finish unofficially at 752.44. The Nasdaq Composite Index .IXIC fell 70.30 points, or 5.07 percent, to close unofficially at 1,316.12. (Reporting by Rodrigo Campos; Editing by Jan Paschal)