South Korea’s largest carmaker Hyundai Motor Co. is estimated to have lost 145.2 billion won ($130.3 million) Saturday as its workers boycotted that day’s overtime shifts, sources said.

According to the sources, Hyundai Motor failed to produce 7,104 cars Saturday as its unionized workers did not show up to work for their weekend work shift.

The move came after Hyundai’s 46,000 union workers staged a partial strike Friday, a day after their leaders failed to work out differences with the management over the latest wage dispute.

Hyundai workers also launched a partial strike on Tuesday and Wednesday, costing the carmaker 85.6 billion won in lost production.

The union and the management have been at odds over the union’s demands for, among other things, a performance-based bonus equal to 30 percent of the company’s net profit last year, which reached 9 trillion won.

The union also called for each child of a worker to receive 10 million won if they choose to enter the workforce following high school instead of pursuing post-secondary education, as well as a hike of 130,498 won in basic salaries and a one-year extension of the retirement age to 61.

Labor disputes at Hyundai Motor have been an almost annual event in the past two decades. Its workers have downed their tools every year since 1986 except for in 1994, 2009, 2010 and 2011. A strike last year cost the carmaker some 1.7 trillion won in lost production. (Yonhap News)