Ford shares tumble on market drop

Shares of Ford Motor Co. are plummeting, pulled down by a steep drop in the overall market resulting from JPMorgan Chase & Co.'s plans to buy Bear Stearns & Co. in a government-backed deal.

The Dow Jones industrials, down nearly 200 points in the early trading, rose into positive territory and then sank again by more than 150 points.

Ford shares dropped as low as $4.95, passing its previous 52-week low of $5.12 set on Thursday, before edging back to $4.99 in afternoon trading.