The firm will remain auditor for the 2019 financial year but will hand over to Big Four rival KPMG on 1 January 2020, subject to shareholder approval at the 2019 agm.
Rio Tinto, which is a FTSE 100 company, says that it chose KPMG following the completion of a competitive tender process.
Commenting on the changeover, Rio Tinto’s audit committee chair Ann Godbehere said, “On behalf of the Rio Tinto board, I’d like to thank PwC for their diligence and dedication over the years.
“We now look forward to working with KPMG.”
PwC was first appointed auditor to the group in 1980. Last year, it earned $18.8m (£14.1m) in fees, including £10.7m from the audit and £3.4m from non-audit services such as tax and assurance.