Rio Tinto has called off a controversial side agreement it had signed with a pair of shareholders that opposed the company's plan to buy a minority stake in Turquoise Hill Resources Ltd. that it does not already own.

The mining giant says it will now work with Turquoise Hill to set a new shareholder meeting date to vote on its offer of $43 per share for the 49 per cent stake it does not already own.

Rio Tinto had reached an agreement with dissident shareholders Pentwater Capital Management LP and SailingStone Capital Partners LLC that would have seen them withhold their votes on the proposal and instead exercise their dissent rights under an arrangement which included mediation and the possibility of binding arbitration.

However, the vote on the takeover deal was delayed after Turquoise Hill's special committee of independent directors raised concerns about the differential treatment of the company's minority shareholders.

The Quebec securities regulator also said the transaction as structured raised public interest concerns.

Turquoise Hill owns a 66 per cent stake in the Oyu Tolgoi copper and gold mine in Mongolia. Erdenes Oyu Tolgoi LLC, a Mongolian state-owned entity, holds the remaining 34 per cent interest.