BHP chairman Ken MacKenzie plans to retire from the board in 2025, kicking off a succession race at the world’s biggest mining company in which former National Australia Bank boss Ross McEwan and Macquarie director Michelle Hinchliffe are among the contenders.

While no final decisions on tenure have been made, Mr MacKenzie plans to honour an informal nine-year limit on directorships at the company, according to people who spoke on the condition of anonymity.