Palliser, an activist investor, is urging Rio Tinto (RIO.US) to reconsider its dual-listing structure.

On Monday, activist investor Palliser Capital sent a letter to Rio Tinto's board urging it to take further steps to unify its dual-listed structure, after a report commissioned by Palliser supported its view that Rio should abandon its primary listing in London and unify its structure as an Australian-registered company.

Palliser said Grant Thornton's report highlighted the price difference between Rio's shares listed in London and Australia, which limited the company's ability to execute major share buybacks and complicated equity financing, supporting the hedge fund's argument that Rio's rejection of its call for a unified listing was wrong and urging its shareholders to vote against the resolution.

Rio said a review it conducted last year found its dual-listed company structure remained effective and beneficial for the company and its shareholders.

The report's conclusion was released ahead of Rio's shareholders voting on Palliser's resolution calling for an independent review of its listing status; Rio's shareholders listed in London will vote on April 3, while those listed in Australia will vote on May 1.

Rio's rival BHP Group (BHP.US) ditched its dual-listed structure in 2022 under pressure from activist investors and now trades mainly in Australia.