An international tribunal is expected to deliver a decision as early as Tuesday night, Korea time, on a multi-billion dollar damages lawsuit pitting the U.S. private equity firm Lone Star against the South Korean government.

According to legal circles, the Washington-based International Centre for Settlement of Investment Disputes will deliver its ruling on Tuesday local time, culminating a decade-long legal battle.

Lone Star filed the investor-state dispute lawsuit in 2012 demanding four-point-six-eight billion dollars in damages from the South Korean government. The company acquired Korea Exchange Bank in 2003 and tried to sell its controlling stake in the bank to global banking giant HSBC in 2007. It eventually ended up selling it to Seoul-based Hana Financial Group in 2010.

Lone Star claims its deal with HSBC fell through because Seoul's regulators deliberately delayed its approval, and that Korean tax authorities also imposed unfair taxes.

The International Centre for Settlement of Investment Disputes has been reviewing the case since 2013. 

The Seoul government has maintained that Lone Star was treated fairly under the same standards as any domestic firm.