Sam Laidlaw, senior independent director of Rio Tinto PLC, and Simon McKeon, senior independent director of Rio Tinto Ltd (ASX:RIO), will jointly lead the search for Thompson's successor after he decided not to seek re-election.
"I am proud of Rio Tinto's achievements in 2020, including our outstanding response to the COVID-19 pandemic, a second successive fatality-free year, significant progress with our climate change strategy, and strong shareholder returns," said Thompson. "However, these successes were overshadowed by the destruction of the Juukan Gorge rock shelters at the Brockman 4 operations in Australia and, as chairman, I am ultimately accountable for the failings that led to this tragic event," he added.
Rio Tinto destroyed the Juukan rockshelters in the Pilbara region of Western Australia in May 2020, damaging its longstanding relationship with the Puutu Kunti Kurrama and Pinikura People - the Tradional Owners of the 46,000-year-old caves.
"Over the past eight months, we have engaged extensively with investors, government, civil society, indigenous leaders and, most importantly, Traditional Owners to learn the lessons from Juukan Gorge," said Thompson.
"We have taken decisive action to address the weaknesses identified in our risk management and governance, while also acknowledging the need to improve our work culture and to rebuild relationships. In January, we appointed a new chief executive, Jakob Stausholm, who has moved swiftly to appoint his new executive team and has identified his key priorities to rebuild the trust that we have lost," he said.
Laidlaw said the board accepted Thompson's decision and was "grateful that he has agreed to provide an important period of stability and support for Jakob and the new executive team ahead of the AGMs in 2022".
"This will allow an orderly process for the appointment of our new chair and other key board members," he added.