GM Korea will accept applications for voluntary retirement from its workers.
As part of an effort to shed production costs and improve the factory's falling productivity, its Gunsan factory's two-shift system will change to one-shift.
The retirement program will be limited to managerial positions. But, coupled with the planned factory system change, unionists are worried that it could be a signal of upcoming large-scale layoffs.
The company conducted a voluntary severance plan in February when some 300 workers left the company.
The scale of the voluntary retirements this time around has not been confirmed, but it is widely speculated to be similar in size and to be done before the end of the year.
Sergio Rocha, GM Korea's CEO, mentioned the Gunsan factory's shift system change during a business presentation to unionists early this month.
The company claims that the current two-shift system could jeopardize the production quota for the next generation Cruze.
In December, GM decided to stop selling its Chevrolet-branded cars in Europe by the end of 2015, a move that hit output at its Korean unit, which produces most of the Chevrolet cars sold there.
Due to the reduced production, the factory's current operation rate remains at 60 percent.
Since the planned Cruze production will begin from 2017 and no additional production quota has been allotted until then, unionists worry that it could lead to massive layoffs.
"We have already agreed with the company to initiate a program where we have reduced production per hour to save jobs. If our factory becomes a one-shift system, the annual production will decrease to half and many will lose their jobs," said a unionist at the Gunsan chapter of the GM Metal Workers' Union.
The two-shift system could produce 230,000 cars a year. But, if it changes to a one-shift system, the annual production could be reduced to 100,000, he said.
He added that the company's demand for the shift change, threatening that it might otherwise lose the planned Cruze production project, is a breach of what had been agreed in this year's collective bargaining.
The company closed this year's wage agreement before others, since it had earned a production quota for the next generation Cruze as well as expanding ordinary wages.
"Globally GM has reduced its factories' capacities prior to close-downs," he said expressing concern.
The company said that there will be no restructuring and layoffs, and the retirement will be done on a voluntary basis.
The union will convene a meeting next week to discuss the matter.