Jean-Paul Luksic, chairman of Chilean mining company Antofagasta, has been appointed as interim chief executive, just a week before the family business is due to announce its 2011 results.
The move follows the unexpected resignation of non-family Marcelo Awad, who had been chief executive of the group since 2004.
Antofagasta, which is listed on the London Stock Exchange, did not give a reason for his exit.