HD Hyundai Heavy Industries' labor union launched a seven-hour partial strike after rejecting management's first offer during the 18th round of wage and collective bargaining negotiations. The proposal included a 105,000 won monthly base-pay increase, including a 35,000 won seniority step increase, a 200% special incentive and a 10 million won payment. The union is seeking a 149,600 won monthly increase, higher bonuses and performance payments equivalent to at least 30% of operating profit. The dispute comes as South Korea's shipbuilding recovery drives record hiring at prime contractors, including Hanwha Ocean, which received more than 3,500 applications for 43 entry-level production jobs, an 82-to-1 ratio. The country's top three shipbuilders posted combined operating profit of 5.8758 trillion won last year and 4.7764 trillion won in the first half of this year, while their order backlog reached about $145.4 billion at end-June. The union plans sequential partial strikes through Sept. 10 and a four-hour all-member strike on Sept. 15, while negotiations continue. The central dispute is whether bonuses should be linked to operating profit, a demand that is also emerging at other shipbuilders even as subcontractors continue to face labor shortages.