* Automakers plunge on bailout worry

* GM, Ford shares drop; investors snap up defensive stocks

* Dow off 2.3 pct, S&P 500 off 3.1 pct, Nasdaq off 3.3 pct

* For up-to-the-minute market news, please click on [STXNEWS/US]

(Updates to midday, changes byline)

By Charles Mikolajczak

NEW YORK, Nov 19 (Reuters) - U.S. stocks tumbled on Wednesday as dimming hopes for a rescue of the U.S. auto industry added to concerns about the deepening economic downturn.

Shares of General Motors GM.N fell nearly 14 percent to $2.66, hitting an intraday low of $2.52, a level not seen in over 60 years. Ford (F.N: Quote, Profile, Research) slumped 17 percent as investors fretted about the possibility that there will be no quick proposal from Congress to resolve the problems plaguing the industry before its session draws to a close.

U.S. auto executives from GM, Ford and Chrysler warned Congress on Tuesday that their industry was teetering on the brink of disaster as they pleaded for a $25 billion aid package despite political opposition to another multibillion-dollar government bailout. [ID:nN18548335] More hearings before a House committee are planned for Wednesday.