Despite of the bid deadline late yesterday, the management of Rio Tinto is still in negotiation with one of the major Riversdale Mining shareholders to assure a majority stake in the Africa-focused mining company. This is after Costas Condoleon, a partner of the law firm representing Rio Tinto, released in a letter the update through the Australian stock exchange.

Although it was not identified which stakeholder is involved, assumptions communicate Rio Tinto may need Cia Siderurgica Nacional’s support to save its $4 billion takeover offer for Riversdale. Cia Siderurgica Nacional (CSN), which recently increased its Riversdale stake to 19.9 percent, is Brazil’s chief steel producer.

CSN said nothing in public of its views about Rio's proposal even with media’s diligent attempts to interview its spokespeople Flavia Ferreira and Edma Nogueira. Rio Tinto’s spokesperson Karen Halbert declined to comment further on the negotiation too. “We’re in discussions,” she said.

Should Rio Tinto have a successful transaction with Riversdale, it would be the mining corporation’s major acquisition since its ill-timed $US38bn takeover of Canadian aluminium producer Alcan in 2007. Furthermore, Rio Tinto would gain control over two major developing coking coal projects in an area of Mozambique attracting interest from mining and steel companies around the world.