General Motors Corp plans to complete a 20 percent cut in its white-collar work force by October, a spokesman said on Tuesday.

An employee is reflected in a General Motors` 

Chevrolet MW, made by Suzuki Motor, at a 
showroom in Tokyo in this June 2, 2009 file photo.

The plan, which was detailed in letters to the bankrupt automaker's employees sent on Tuesday, will eliminate another 4,000 jobs through a combination of layoffs and terminations.

This is what we've talked about - a leaner organization with fewer levels of management, said GM spokesman Tom Wilkinson. You start to see what the new organization will look like.

GM has said it plans to cut 20 percent of its remaining white-collar jobs as it sheds its Hummer, Saab and Saturn brands and slashes manufacturing capacity.

The automaker also plans to cut 35 percent of its more senior executive ranks.

By the end of the process, GM plans to have 23,500 white-collar workers in the United States. That would be down from more than 49,000 in 2000 and down from just over 29,600 at the start of the year.

GM salaried workers have until August to indicate if they are interested in taking severance of up to six months of pay, depending on their length of employment. Other job cuts will be made through firing.

GM has cut its unionized factory work force even more deeply and its cost-cutting actions have accelerated in bankruptcy.

The automaker has slashed 60,500 U.S. factory jobs since 2006, more than half of its factory work force. Workers represented by the United Auto Workers are also being offered another round of buyouts this month.