The Financial Times reports that mining giant Rio Tinto’s shareholders may vote against a proposed joint venture with BHP Billiton.

In June, diamond mining giants Rio Tinto and BHP Billiton announced plans to merge and pool their Western Australian iron ore assets in June, following Rio’s cancelled talks with Chinalco regarding a $19.5bn investment.

Regarding the joint venture, Citigroup stated: "With the rights issue successfully completed and significant progress made on the asset sale process, there is no longer the balance sheet pressure for Rio to do the joint venture."

Citigroup believes that if the proposed deal is discarded, BHP may make another takeover bid for Rio Tinto. The Financial Times quoted Citigroup: "Diamond miner Rio is still the deal that makes the most sense for BHP given the synergies, asset quality and growth options."