An international tribunal has wrapped up the first round of hearings in a multi-billion-dollar case the U.S. private equity firm Lone Star filed against South Korea over disputes surrounding its asset sell-offs in Korea.

Both sides largely repeated their existing positions during the hearings that began on May 15 and were wound up Saturday at the International Centre for Settlement of Investment Disputes in Washington, sources said.

"I heard that our government team did its best and offered good explanations," a source said.

The case is the latest and the biggest in a series of legal battles involving Lone Star's investments in South Korea, including the 2003 purchase of a controlling stake in Korea Exchange Bank, and its sell-off of those assets for large margins.

Lone Star is demanding South Korea pay it nearly US$4.68 billion, claiming it was forced to pay unfair taxes and suffered losses due to Seoul's delay in approving a profitable deal. It represents the first investor-state dispute filed against South Korea's government.

The case has drawn keen attention on South Korea not only because of the amount of money involved but also its possible repercussions amid concern that if the country loses in the case, it could spark similar suits by foreign firms.

South Korea has handled the case after forming an interagency team comprising the Office for Government Policy Coordination, the finance ministry, the foreign ministry, the justice ministry, the National Tax Service and the Financial Services Commission.

A second round of hearings is scheduled to take place for 10 days starting June 29. (Yonhap)