Seoul. South Korea’s top court on Thursday ordered a third Japanese company to compensate some of its former wartime Korean employees for forced labor, the second such ruling in a week.

The South Korean verdict drew quick rebukes from Japan, but observers say it’s unlikely the ruling will cause any major negative impacts on bilateral relations, as both governments are serious about improving their cooperation in the face of shared challenges like North Korea's nuclear program and China's assertiveness.

The Supreme Court ruled that shipbuilder Hitachi Zosen Corp. and heavy equipment manufacturer Mitsubishi Heavy Industries must give between 50 million won (about $39,000) and 150 million won (about $116,000) in compensation to each of the 17 Korean plaintiffs -- one of whom is a surviving ex-worker and the rest bereaved relatives.

Mitsubishi and another Japanese company, Nippon Steel, were previously given a similar compensation order by the South Korean court, but it was the first such ruling for Hitachi.

Among the plaintiffs are the surviving victim who suffered a serious burn and the bereaved family of a worker who died during an earthquake in Japan in 1944, when they worked for Mitsubishi’s aircraft-making factory in Nagoya. Others include the relatives of late Mitsubishi workers who were injured during the US atomic bombing of Hiroshima and another wartime event, according to a court press release.

A ruling in favor of Korean plaintiffs was widely expected because the Supreme Court in two separate rulings in 2018 ordered Mitsubishi and Nippon Steel to compensate some of their former Korean employees, saying they were forced to provide their labors to the companies when the Korean Peninsula was colonized by Japan from 1910-45.

On Dec. 21, the top court again ordered Mitsubishi and Nippon Steel to provide compensation to other Koreans for similar colonial-era forced labor.

Japan’s Foreign Ministry responded by summoning a senior South Korean diplomat in Japan to lodge a formal protest. In the meeting, Hiroyuki Namazu, director-general for the Japanese Foreign Ministry’s Asian and Oceanian Affairs Bureau, called the latest South Korean ruling “extremely regrettable and absolutely unacceptable," according to the Japanese ministry.

Namazu maintained Japan's long-held position that all compensation issues between the two countries were settled when they normalized ties in 1965.

The South Korean rulings in 2018 and this month argued that the treaty can’t prevent individuals from seeking compensation for forced labor because Japanese companies’ use of such laborers were “acts of illegality against humanity” that were linked to Tokyo’s illegal colonial occupation and its war of aggression.

The 2018 rulings plunged bilateral ties to one of their lowest ebbs in decades. Japan imposed export restrictions on key items, while South Korea threatened to terminate a military intelligence-sharing pact with Japan. But their ties began improving significantly in 2023 after South Korea's government, now led by conservative President Yoon Suk Yeol, established a domestic fund to compensate forced labor victims without demanding Japanese contributions.

Eleven of the 15 former forced laborers or their bereaved families involved in the 2018 rulings had accepted compensation under Seoul’s third-party reimbursement plan, but the remaining four refused to accept it. Lim Soosuk, spokesperson of South Korea’s Foreign Ministry, said the government would seek to provide compensation to the Korean plaintiffs related to Thursday’s ruling through the third-party reimbursement system as well.