Under the agreed terms, Rio Tinto will pay C$43 ($32.7) for each share in cash to Turquoise Hill’s minority shareholders.
Turquoise Hill’s independent directors have unanimously recommended its minority shareholders vote in favour of the deal, which is supported by the directors and the company’s senior officers.
Turquoise Hill owns a 66% stake in the Oyu Tolgoi copper-gold mine in Mongolia. The remaining 34% stake in the Mongolian mine is held by the state-owned Erdenes Oyu Tolgoi.
Rio Tinto copper CEO Bold Baatar said: “Rio Tinto will work in direct partnership with the Government of Mongolia and Erdenes Oyu Tolgoi to realise the full potential of the Oyu Tolgoi project for the benefit of all stakeholders.
“This transaction rewards all minority shareholders with an exceptional premium of 67% for their shares and brings the financial certainty necessary to ensure the Oyu Tolgoi project can be developed without having to ask minority shareholders to contribute further significant funds.”
Rio Tinto CEO Jakob Stausholm said: “This transaction will simplify governance, improve efficiency and create greater certainty of funding for the long-term success of the Oyu Tolgoi project.
“Rio Tinto’s offer guarantees Turquoise Hill’s minority shareholders outstanding value through a significant all-cash premium for their shares.
“After extensive negotiations, the terms of the transaction are final and there will be no further price increase.”
The deal is expected to close in the fourth quarter of this year subject to certain closing conditions being met.
It requires the approval of 66.67% of Turquoise Hill’s shareholders and that of a majority of Turquoise Hill’s minority shareholders.
Earlier this year, Rio Tinto and Turquoise Hill reached an agreement with the Mongolian government to proceed with the $6.93bn Oyu Tolgoi underground project.