Workers on the morning shift leave Hyundai Motor’s Ulsan plant through the Myeongchon main gate in Buk-gu, Ulsan, two hours earlier than usual on July 13, amid the union's partial strike. (Yonhap) Hyundai Motor’s union ramped up pressure on the automaker Monday by launching a second round of partial strikes as wage talks with South Korea’s largest automaker remained stalled.Members of the Hyundai Motor branch of the Korea Metal Workers’ Union said it will halt work for four hours at the end of each shift from Monday through Wednesday, up from two hours per shift during their first round of strikes last week.The morning shift will suspend production from 10:50 a.m. to 3:30 p.m., while the evening shift will stop work from 7:30 p.m. until 12:10 a.m. Excluding scheduled meal and break periods, each shift will stage a four-hour walkout, bringing the total daily work stoppage to eight hours.The latest action marks the union’s second partial strike of the year and its second straight week of work stoppages. Union members had already walked out for two hours per shift from July 13 to 15.The union said it decided to escalate its industrial action because Hyundai Motor had neither presented a revised offer nor formally requested that negotiations resume. It added, however, that it would suspend a scheduled strike if formal talks restart.The union also plans to continue refusing weekday overtime and weekend work, adding further pressure on vehicle production. Industry estimates suggest the two rounds of walkouts could result in combined production losses of about 15,000 vehicles and roughly 650 billion won ($439 million) in lost revenue if the union carries out the strikes as planned.The estimates are based on last year’s 16-hour partial strike, which reportedly affected about 7,000 vehicles and cost more than 300 billion won in sales.The strike came after a last-ditch round of intensive negotiations failed to produce a compromise, despite holding 15 rounds of talks this year.At that meeting, the company presented its third offer, which included an increase of 89,000 won in monthly base pay, a performance bonus equal to 350 percent of monthly base pay, 10 million won in cash and 15 Hyundai Motor shares for each employee.The union rejected the offer, saying it fell short of workers’ expectations.It is demanding a monthly base-pay increase of 149,600 won, excluding regular seniority-based raises, and a performance bonus equivalent to 30 percent of the company’s 2025 net profit.The union is also seeking guarantees that management will consult the union before deploying Boston Dynamics' Atlas humanoid robots at Hyundai Motor’s production facilities.Despite the walkout, the two sides are said to be continuing informal discussions to reach a settlement. The union plans to review the state of the talks Thursday before deciding whether to extend the strike or escalate its labor campaign.