The chairman of Samsung Electronics Lee Kun-hee has won a case brought by his brother, who was demanding an $850m (£522m) share of his inherited wealth.
Lee Kun-hee was accused by Lee Maeng-hee of hiding company shares after their father, Samsung's founder, died.
But on Thursday Seoul's High Court upheld the original verdict which found in favour of Lee Kun-hee.
Lee Maeng-hee's lawyer said his client had not yet decided whether to take his case to the Supreme Court.
The High Court found that some of the shares in the Samsung Group claimed by Lee Maeng-hee had been left to him by his father, Lee Byung-Chull, when he died in 1987.
But it said the 10-year period for inheritance claims had expired.
A ruling against the chairman - who is also South Korea's richest man - could have diluted his grip on one of the country's biggest companies.
Lee Maeng-hee and other relatives had filed a $4bn claim against Lee Kun-Hee in 2012, arguing he had hidden shares in other people's names.
The other family members chose not to continue with their claim after a lower court ruling against them last year.
The Samsung chairman accused his brother of becoming jealous as the company grew into a global brand.
Lee Byung-Chull, who founded Samsung in 1938 selling dried fish in South Korea, had three sons and five daughters.
Under Lee Kun-hee's leadership, Samsung has grown into the world's biggest maker of mobile phones and televisions.
In 2008, Lee Kun-hee was convicted of tax evasion, which led him to resign as chairman of the company.
But he received a presidential pardon in 2009 and returned to lead Samsung Electronics in 2010.