The White House declined to comment on the decision by top General Motors Corp. (GM) executives to sell their shares in the struggling auto maker.

"I think it's probably better that I resist the temptation to comment on individuals' stock holdings," White House spokesman Robert Gibbs said Tuesday.

Late Monday, six GM executives reported the sale of all the company stock they owned. The biggest seller was Vice Chairman Bob Lutz, according to filings with the Securities and Exchange Commission. He sold 81,360 shares for $130,990.

The news helped send GM shares to their lowest level since 1933 Tuesday as investors bet the company is likely to lose its fight to stave off bankruptcy. Chief Executive Fritz Henderson said Monday that a bankruptcy is "more probable."

The company faces a government-imposed June 1 deadline to reach a pact with workers and creditors that keeps it out of bankruptcy court.

Gibbs said President Barack Obama and his automotive task force are still working for a deal that saves the company.

"The task force will continue to work with General Motors to get a plan they believe puts it on a sustainable path," the spokesman said. "The president and the task force want to ensure the continuation of General Motors" in a way that doesn't involve continued government aid.

The company's stock recently traded at $1.12, down 22%.

-By Henry J. Pulizzi, Dow Jones Newswires; 202-862-9256; henry.pulizzi@dowjones.com