Mohammad Barkindo, Nigerian politician and secretary-general of oil producer group OPEC, has died at the age of 63.
His second term as head of OPEC was set to end in three weeks on July 31.
He'd held the post for six years since 2016.
OPEC's 13 member-states have 1.24 billion proven crude oil reserves among them, or 80% of the world's share.
Saudi Arabia is by far the biggest exporter of crude within OPEC, with 6.23 million barrels per day of crude exports last year. Non-OPEC producer, Russia, exported 4.5 million barrels of crude last year.