Ravil Maganov, chairman of Russia's second-largest oil producer Lukoil, died on Thursday after falling from a hospital window in Moscow, a source familiar with the situation told Reuters.
Some Russian media also reported the death of Maganov, 67, who was also Lukoil's vice president, citing unnamed sources.
No immediate comment was available from Lukoil.
Maganov had worked in Lukoil since 1993, shortly after the company's inception, and had overseen its refining, production and exploration, becoming chairman in 2020. His brother Nail is the head of mid-sized Russian oil producer Tatneft.
Ravil Maganov was a close associate of one of Lukoil's founders, Vagit Alekperov.
Alekperov, a former Soviet deputy oil minister, resigned as president of Lukoil in April, a week after Britain imposed an asset freeze and travel ban on him as part of sanctions over Russia's military actions in Ukraine.