Seoul: The Supreme Court on Wednesday upheld parts of lower courts' rulings in favor of residents of Yongin, about 40 kilometers south of Seoul, who launched a damages lawsuit over a controversial light rail system that they argue has cost the city over 1 trillion won (US$720 million) in losses.

According to Yonhap News Agency, in February last year, the Seoul High Court ruled that the current mayor of Yongin could charge 21.4 billion won in compensation from former Yongin Mayor Lee Jeong-moon, the Korea Transport Institute (KOTI), and a KOTI researcher over the transit system. The system has put the municipality into financial trouble due to a low usage rate. The high court found Lee guilty of committing grave negligence by concluding an agreement that was highly favorable to its Canadian developer in 2004.

The Supreme Court approved the high court rulings concerning the liabilities of Lee and KOTI but ordered a retrial of the KOTI researcher, stating that further court hearings will be needed over the individual researcher's liability.

The Yongin EverLine, which connects Everland, the country's largest theme park, to Giheung Station on the Suin-Bundang Line, opened to the public in 2013. This was nearly three years after its completion due to a dispute with the Canadian developer over the issue of minimum revenue guarantee. The city eventually lost in international arbitration, paying the developer some 850 billion won, along with additional expenses.

The transit service has suffered significant losses as the number of users was far lower than predicted by KOTI.