A joint takeover bid for Aquila by China's Baosteel and local rail operator Aurizon has moved a step closer, with another key shareholder poised to accept the $1.4 billion offer.
Aquila co-founder Charles Bass, who holds a 10.7 per cent stake in the takeover target, intends to take up the offer in early July.
The company's chairman Tony Poli, who holds 28.9 per cent stake, has already said he intends to accept the offer.
However, both men say they reserve the right to change their minds.
"Upon Mr Bass and Mr Poli accepting the offer (in accordance with their current statements of intention), the bidders will have a relevant interest in Aquila of over 50 per cent, and the minimum acceptance condition of the Offer will be satisfied," Baosteel and Aurizon said in a statement on Wednesday.
Baosteel and Aurizon have seen off a rival bid for Aquila from Mineral Resources, which holds just under 13 per cent of the explorer.
The pair were keen to take control of Aquila so they can kickstart the stalled $10 billion West Pilbara Iron Ore Project.
Mineral Resources has said it wants to discuss its potential involvement in the construction of the mine, rail and port project, as well as the operation of the mines as it considers what to do with its stake in Aquila.
Aquila shareholders have until July 11 to accept the offer from Baosteel and Aurizon.