Shares in Royal Bafokeng jumped 16% on the news, while Impala shares were down 2.5% on the Johannesburg Stock Exchange by 0850 GMT.

The companies have completed reciprocal due diligence and are progressing a proposed transaction implementation agreement, they said, adding shareholders would be kept informed of developments.

Implats produced 2.8 million ounces of refined platinum group metals in its 2020 financial year, while RBPlat produced 419,000 ounces of PGMs in 2020.

Soaring prices for platinum, palladium and rhodium this year have cushioned PGM producers' cash balances, spurring companies like Sibanye Stillwater to hunt for acquisitions.

Macquarie Advisory and Capital Markets South Africa is the financial advisor to Implats on the deal.

(Reporting by Helen Reid;Editing by David Goodman and Emelia Sithole-Matarise)