MELBOURNE/LONDON (Reuters) -Rio Tinto said on Thursday that more than 80% of its shareholders had voted against a review of the mining company’s dual-listed structure, in line with its board’s recommendations.

The mining giant said 19.35% of shareholders had voted for the motion, just shy of the 20% threshold that would have required it to consult more widely with shareholders under UK regulations.

The motion was put forward by London-based activist investor Palliser Capital. It wants Rio Tinto (NYSE: RIO ), which is listed in London and in Sydney, to unify into a single holding company in Australia.

"Rio Tinto will continue to engage with our shareholders and will carefully consider the feedback provided," the company said in a statement.

Palliser has argued that doing away with the current structure could unlock $28 billion in value for holders of Rio Tinto’s London shares.

Holders of its Australian stock voted on Thursday and holders of its UK shares voted at the London AGM on April 3.

The London listing comprises about 77% of Rio Tinto’s investor base, but the Australian-listed shares are trading at a premium of about 25%, partly due to tax advantages available to Australian shareholders.

Rio Tinto’s board had unanimously recommended voting against the resolution, citing tax considerations and saying that a unified listing is not required to provide it with strategic flexibility.

Palliser’s motion was backed by influential proxy adviser firms Institutional Shareholder Services (ISS) and Glass Lewis and more than 100 other shareholders including Norway’s sovereign wealth fund Norges Bank Investment Management.

Rival BHP ended a similar dual-listed structure in 2022 and now has a primary listing in Australia, six years after activist investor Elliott began its campaign for a single listing.