Samsung Electronics vice chairman Jay Y. Lee's defense lawyer has filed to appeal against a five-year jail term for bribery handed down by a lower court, the Seoul Central District Court's website has said.
A Samsung spokeswoman did not have any immediate comment about the appeal against the sentencing handed down on Friday.
The sentencing on 25 August of the billionaire scion was a significant moment for South Korea's decades-long economic order, which has been dominated by powerful, family-run conglomerates.
After a six-month trial over a scandal that brought down the then president, Park Geun-hye, a court ruled last week that Lee had paid bribes in anticipation of favours from Park.
The court also found Lee guilty of hiding assets abroad, embezzlement and perjury.
Lee, the 49-year-old heir to one of the world's biggest corporate empires, had been held since February on charges that he bribed Park to help secure control of a conglomerate that owns Samsung Electronics, the world's leading smartphone and chip maker, and has interests ranging from drugs and home appliances to insurance and hotels.
Lee denied wrongdoing, and one of his lawyers, Song Wu-cheol, said he would appeal.
"The entire guilty verdict is unacceptable," Song said at the time, adding he was confident his client's innocence would be affirmed by a higher court. The case is expected to be appealed all the way up to the Supreme Court, likely next year.
Under Korean law, Lee can be kept in detention a maximum four months while a court considers his appeal.
On Monday, shares of Samsung Electronics fell more sharply than the wider Korean market. At 0407 GMT, the share was down 1.6 per cent, compared with a 0.4 per cent drop for the benchmark Kospi index.
(Reporting by Joyce Lee; Editing by Paul Tait and Richard Borsuk)