The Czech Republic's richest man, billionaire Petr Kellner, was killed in a helicopter crash in Alaska, his financial group PPF said on Monday. He was 56.
PPF said five people died in the crash, whose circumstances were being investigated.
"We announce with the deepest grief that, in a helicopter accident in Alaska mountains on Saturday, March 27, the founder and majority owner of the PPF group, Mr Petr Kellner, died tragically," PPF said in a statement.
Kellner was a towering business figure of the Czech post-communist era, with his wealth estimated at $17.5 billion according to Forbes.
Prime Minister Andrej Babis offered his condolences to the family. "Unbelievable tragedy. I am very sorry," Babis said on Twitter.
Kellner's roots go back to the 1990s when he set up PPF as an investment company with partners to take part in the country's scheme to privatise hundreds of state-owned companies. In the mid-1990s, PPF took a stake in former national insurer Ceska Pojistovna, a springboard for further growth.
PPF went on to grow in finance, telecommunications, manufacturing, media or biotech in businesses spanning mainly Europe, Asia and the United States. PPF's assets amounted to 44 billion euros ($51.8 billion) by mid-2020.
PPF is the main owner of consumer lender Home Credit, which has grown in China and elsewhere in Southeast Asia as well as a group of telecommunications firms in central and eastern Europe including O2 Czech Republic.
His death came at a time when PPF was acquiring a stake in Czech bank MONETA Money Bank and proposing to merge it with his Air Bank and the Czech and Slovak assets of Home Credit. PPF's telecomunications infrastructure firm Cetin has also said it was considering a public offering and other options.
PPF completed the acquisition of Central European Media Enterprises, a group of television stations in central and eastern Europe, last year.
Kellner had avoided public attention but was known to be a keen skier. PPF published a picture of him snowboarding in one of its annual reports.
Alaska State Troopers said on Sunday that five people including Kellner were killed and one injured in a helicopter crash near Knik Glacier northeast of Anchorage.
The helicopter was ferrying skiers who had been on a backcountry tour, the troopers said.