Samsung Electronics co-chief executive officer Han Jong-hee died of cardiac arrest on Tuesday, the South Korean tech giant said. Han Jong-hee was 63.

Han died at a hospital while being treated for cardiac arrest, a company spokesperson said. The company is yet to name a successor.

News agency Reuters reported that 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.

Samsung Electronics shares were flat in morning trade.

This is a developing story. More details are awaited.