Rio Tinto does not support a push by some shareholders to consolidate the company's dual-exchange share listing in Sydney, its CEO told Reuters on Wednesday as the miner reported its smallest full year underlying earnings in five years.

Rio Tinto Group has rebuked a call from activist investor Palliser Capital UK Ltd. to unify its dual listing into an Australian-domiciled holding company, saying tax costs would amount to billions and there was nothing to gain.