In the latest talks, the two sides failed to narrow the gap running deep between them over wages. They plan to have the 37th talks on Thursday, the spokesman said.

From Wednesday to Friday, Hyundai workers will walk out for six hours a day at the Ulsan plants, he said.

Hyundai Motor currently operates seven plants in Korea, including five in the port city of Ulsan. It has also production facilities in the United States, Europe and emerging countries such as China, India and Russia.

In the wage talks that have yet to be concluded, the union has demanded Hyundai raise workers' basic monthly wages by 154,883 won ($142) and offer a bonus of 30 percent of the company's 2016 full-year net profit of 5.72 trillion won.

Citing an unfriendly business environment, however, the company offered to raise basic salaries by 42,879 won per month and to provide bonuses worth 200 percent of basic pay plus 1 million won.

When the offer was rejected by the union, the company suggested bonuses of 250 percent of basic pay plus 1.5 million won in extra compensation as a revised offer.

This year, Hyundai workers have staged strikes that cost the company about 800 billion won in lost production -- the equivalent of 38,000 vehicles -- the company said. 

Labor strikes have plagued the country's biggest carmaker for decades. Its workers have walked out every year since 1986 except for in 1994, 2009, 2010 and 2011. (Yonhap)