Unionized workers at Hyundai Heavy Industries, the nation’s top shipbuilder, staged a partial strike on Thursday for the first time in 20 years over an annual pay dispute with the management.

The negotiations between the two sides have been deadlocked since May despite more than 50 rounds of talks to reach an agreement on pay and incentives for 2015.

Unionized workers gathered at the company’s headquarters located in the southeastern port city of Ulsan and went on a strike for four hours from 1 p.m. It is the shipbuilder’s first collective action since 1994.

According to the HHI labor union, more than 6,000 workers participated in the strike and the production lines in Ulsan were halted.

Along with other issues, the union is demanding a 132,000 won ($120) raise in basic pay but the company suggested only 37,000 won.

On Wednesday chief executive officer Kwon Oh-gap said that the company’s management cannot offer additional pay raise due to its lackluster earnings. 

“The company will compensate workers when the situation improves and the company makes higher profits,” he said in a statement ahead of its 52nd round of negotiations held on the day.

Kwon took the helm in September with a clear mission to save the company from the worst performance in its history ― a cumulative operating loss for this year, from the first to third quarter, reaching 3.2 trillion won.

HHI posted the biggest operating loss of 1.9 trillion won in the third quarter of this year. Its local rivals Samsung Heavy Industries and Daewoo Shipbuilding & Marine Engineering on the other hand have gained in the last two quarters.

The union sees the company’s poor management as the main cause for its worst ever performance, saying it was excessively tapping into low price orders in building ships and offshore plants.

“The company is passing the buck to workers for what they call a ‘crisis’ but the misfortune is invited by its own poor management,” a unionist said.

“The company is touting the wage proposal that was even voted down in its affiliates like Hyundai Mipo Dockyard and Hyundai Samho Heavy Industries.”

Kwon acknowledged management faults in the worsened business performance and offered to return his wages to the company until the situation gets better.

Meanwhile, it was announced that the union and management of HHI will continue their negotiations despite the strike.

By Park Han-na (hnpark@heraldcorp.com)