Washington - The struggling Big Three US carmakers on Tuesday submitted the recovery plans demanded by Congress, in their bid for a federal bail-out, even as monthly car sales in the United States tumbled more than 30 per cent.

Legislators last month spurned the carmakers' request for a total of 25 billion dollars to help them continue restructuring and avoid bankruptcies that could cost millions of jobs in the United States. Congressional leaders last month said they needed more concrete details on the companies' recovery plans before considering the bail- out.

Ford Motor Co unveiled its 33-page business plan Tuesday morning, requesting a 9-billion-dollar "bridge loan" to rescue it from a US recession and credit crunch that have sharply curbed car sales.

General Motors Corp asked for 12 billion dollars in its own business plan with an option for an additional 6 billion dollars in loans "should a severe market downturn persist." Four billion dollars are already needed this month.

"Government loans would serve as a critical backstop or safeguard against worsening conditions, as we drive transformational change in our company," chief executive Alan Mulally said in a statement.

Ford, generally regarded as in the best shape of the three major US car companies, said it would not necessarily need to access the government's cash infusion if markets improved in the coming months.

By contrast, both General Motors and Chrysler LLC may not have enough money to continue daily operations beyond 2008 without the government rescue.

The proposals come as November sales plunged by 35 per cent industry wide, compared to the same month in 2007. GM's sales dropped 41 per cent, Chrysler's plummeted 47 per cent, Ford's were down 30 per cent, and Japanese giant Toyota Motor Corp said that US sales fell 34 per cent.

"2008 will go down as unlike any other year in the industry," Chrysler Vice Chairman Jim Press said.

Car sales have dropped to their lowest levels in 25 years as consumers struggled to get automotive loans, but lawmakers have argued that Detroit's antiquated business model put the Big Three in dire straits even before the current economic crisis began.

The heads of Ford, GM and Chrysler will appear before Congress for hearings on Thursday and Friday to discuss their newest proposals.

Nancy Pelosi, speaker of the House of Representatives, said that the carmakers' plans were still being reviewed. She said that legislators could return to session this month to reconsider the bail-out, if the proposals from Detroit are seen as viable.

She called bankruptcy "not an option."

Treasury Secretary Henry Paulson, who has already shovelled hundreds of billions of dollars to crisis-stricken banks on Wall Street, agreed: "We need a solution that avoids bankruptcy, but it's got to be leading to a viable industry."

The Big Three have warned that bankruptcy could cost millions of jobs and insisted that their recoveries, which primarily involve a shift to more fuel-efficient vehicles, had been well under way before the financial crisis struck.

Ford's Mulally and GM chief Rick Wagoner offered to accept salaries of 1 dollar for one year and to forego management bonuses in exchange for the government loans. Ford said it would sell its five corporate jets.

When the three chief executives first pleaded for a bail-out last month in front of Congress, their arrival in Washington in private jets provoked public outrage. This time, each has promised to make the more than 800-kilometre trip in petrol-electric hybrid cars.