A legendary American automobile bites the dust.

The president of General Motors announced his plans Monday to discontinue production of its celebrated Pontiac brand and cut 21,000 factory jobs by next year as part of a massive restructuring effort needed to secure more government aid.

Pontiac -- in business since 1926 -- became a symbol of American muscle cars with Hollywood's glorification of it in the movie "Smokey and the Bandit" and the television show "Night Rider."

"We just didn't have a strategy that we were satisfied with that could allow us to win with the Pontiac brand," GM CEO and president Fritz Henderson said during a morning news conference Monday at the automaker's headquarters in Detroit.

"We could not provide the marketing muscle behind the brand," added Henderson, who said the decision was "tough" because "the brand has a considerable heritage within our company."

Henderson also said the automaker will also offer 225 shares of common stock for every $1,000 in notes held by bondholders as part of a debt-for-equity swap.

Click here for photos of the Pontiac line.

In response to GM's restructuring plans, the White House released a statement Monday, saying, "Today's bond exchange filing represents an important step in GM's effort to restructure its company."

"The interim plan that GM laid out in this filing reflects the work GM has done since March 30 to chart a new path to financial viability. We will continue to work with GM's management as it refines and finalizes this plan and with all of GM's stakeholders to help GM restructure consistent with the President's commitment to a strong, vibrant American auto industry," the White House said.

GM is living on $15.4 billion in government loans and faces a June 1 deadline to restructure and get more government money. If the restructuring doesn't satisfy the government, the company could go into bankruptcy protection.

GM said the bond exchange aims to wipe away a large majority of the company's $27 billion in unsecured debt. The company estimates that after the exchange, bondholders would own 10 percent of the company.

In addition, GM is offering the United Auto Workers stock for at least 50 percent of the $20 billion the company must pay into a union run trust that will take over retiree health care expenses starting next year.

All the stock offerings mean that current common stockholders would own only 1 percent of the company under the deals, the press release says.

In premarket trading, GM shares rose 7 cents, or 4.1 percent, to $1.76.

GM said it would speed up six additional factory closings that were announced in February, although it did not identify them in its news release. Additional salaried jobs cuts also are coming, beyond the 3,400 in the U.S. slashed last week.

Including previously announced plant closures, the restructuring will leave GM with 34 factories at the end of next year, down from 47 at the end of 2008.

The company also said it plans to thin its dealership ranks by 42 percent from 2008 to 2010, cutting them from 6,246 to 3,605.

"The Viability Plan reflects the direction of President Obama and the U.S. Treasury that GM should go further and faster on our restructuring," GM CEO Fritz Henderson said in a statement.

"This stronger, leaner business model will enable GM to keep doing what it does best -- provide great new cars, trucks and crossovers to our customers, and continue to develop new advanced propulsion technologies that are vital for our country's economy and environment."

The new plan lowers GM's break-even point in North America to an annual U.S. sales volume of 10 million vehicles, the company said. That's slightly more than the current sales rate, and most economists expect an uptick in the second half of the year.

"This lower break-even point better positions GM to generate positive cash flow and earn an adequate return on capital over the course of a normal business cycle, a requirement set forth by the U.S. Treasury," the statement said.

FOX News' Major Garrett and the Associated Press contributed to this report.