General Motors Corp.'s (GM) shares, trading above $40 less than two years ago, fell to $1 in early trading Wednesday amid concerns it will file for bankruptcy.

GM's fall came as the broader market sank on worse-than-expected retail sales data for April.

But the auto maker's share price has fallen sharply as it faces a June 1 deadline by the Obama administration to substantially restructure its balance sheet or file for bankruptcy protection.

Even if GM avoids bankruptcy, existing shareholders would be all but wiped out. The company's out-of-court restructuring strategy hinges on a plan that would use new share offerings to pay off creditors.

On Monday, six of GM's top executives disclosed they sold more than $300,000 in company stock.

GM shares recently rebounded to $1.14. The stock is down about 95% over the past year and has dropped 65% since the start of the year.

Shares of Ford Motor Co. (F) also fell this week following the company's announcement Monday it will offer 300 million shares to help fund retiree health-care benefits in a move that would dilute shares outstanding by about 13%. Shares were trading recently at $4.78, down nearly 30% from Friday when shares hit a nine-month high.

-By Sharon Terlep, Dow Jones Newswires; 248-204-5532; sharon.terlep@dowjones.com.