Atherley, who has been chief executive since June 2015, intends to concentrate on his other investments in the resource sector.
"It has been a great pleasure to work with the very talented team in Spain over the past few years and it makes enormous sense to capitalise on the growing interest in the company in Spain where it is now firmly established as the only listed mining company in the birthplace of Rio Tinto and modern mining as we know it today," Atherley said.
Berkeley continues to focus on the progression of the approvals process, so that it can start building the Salamanca mine and bring it to production.
The company also plans to advance its battery metals exploration strategy.
Robert Behets, previously non-executive director, will take the role of acting managing director with immediate effect, supported in Spain by chief operating officer Francisco Bellón.
For longer term succession, Berkeley will seek a to recruit a suitably qualified Spanish national.
Following on from the group’s 2018 stock market listing in Spain the new management appointment will aim to further enhance the company's strong engagement with its key stakeholders in the country.