Anglo American chief executive Cynthia Carroll is to step down after six years in the job.
Earlier this year a group of shareholders, unhappy with a sharp drop in profits, asked the chairman to look for a new chief executive.
Anglo said it was her decision to leave. No date has been set for her departure.
A geologist by training, Ms Carroll was the first non-South African to be appointed to the role in 2007.
The BBC reports she has been under increasing pressure from investors over the company's share price, which has fallen by a third this year.
A wildcat strike by miners in South Africa means the company is losing output of 4500 ounces of refined platinum every day.
