SEOUL -- South Korean tech giant Samsung Electronics said on Tuesday that its co-chief executive officer Han Jong-hee has died due to cardiac arrest. Han was 63.

Han was in charge of Samsung's consumer electronics and mobile devices division, while co-CEO Jun Young-hyun oversees the chip business of South Korea's biggest company.

Han passed away at a hospital on Tuesday while being treated for cardiac arrest, a company spokesperson said, adding that a successor had not yet been decided.

Samsung Electronics shares were flat in morning trade.

The South Korean firm has been suffering from weak earnings and sagging share prices in recent quarters after falling behind rivals in advanced memory chips and contract chip manufacturing, which have enjoyed strong demand from AI projects. Samsung has also ceded its smartphone market crown to Apple.

Han, who joined Samsung Electronics nearly 40 years ago, built his career in the TV business. He became vice chairman and CEO of Samsung Electronics in 2022. Han was also one of the company's board members.

He chaired Samsung's shareholder meeting last week, where he and other executives were grilled by shareholders after the company's failure to ride an artificial intelligence boom made it one of the worst-performing tech stocks last year.

In semiconductors, Samsung lags behind SK Hynix in HBM chips that Nvidia and others rely on for AI graphic processing units.

"First and foremost, I sincerely apologise for the recent stock performance not meeting your expectations. Over the past year, our company failed to adequately respond to the rapidly evolving AI semiconductor market," Han said.

He was scheduled to attend Samsung's launch event for new home appliances on Wednesday.