DETROIT — About 7,500 General Motors workers — roughly 12 percent of the automaker's U.S. hourly work force — have signed up to take buyout and early retirement incentives to leave the company, GM said today.

Also, Chrysler said today it would extend its deadline to entice blue-collar workers to leave. The old deadline was Friday.

GM offered $20,000 cash and a $25,000 voucher to buy a car to all of its 62,400 hourly U.S. employees in an effort to further trim its blue-collar work force to match reduced sales.

Most of those who chose to leave took early retirement offers, said a person familiar with the numbers who did not want to be identified because the breakdown had not been made public. There were very few who took the buyouts, the person said.

The deadline to decide was Tuesday, and many of the workers waited until the last minute to turn in their paperwork, the person said. The workers have seven days from the date they turn in the paperwork to rescind their decision, so many will have to decide by Tuesday.

For those who will leave, the effective date of their departure is no later than April 1, GM said in a statement.

Both GM and Chrysler are living on a total of $17.4 billion in government loans and are seeking another $21.6 billion. The Obama administration's auto task force indicated it might offer more aid, but further concessions are possible from both the companies' stakeholders.

Both companies have to submit finalized restructuring plans to the federal government by Tuesday.

The latest round of buyouts and early retirements at GM was the third for the company since 2006. From all three offers, more than 60,000 workers have decided to leave the company.