The project is estimated to have 320 million tonnes of reserves, with mining capacity at four million tonnes per year, Hoa Phat said in a statement.

A Hoa Phat spokesperson declined to disclose financial details, citing a confidentiality agreement.

Hoa Phat said it was also looking to acquire coking coal mines and more iron ore projects in Australia to fulfil at least 50% of its demand, equivalent to 10 million tonnes of steel per year.

Founded in 1992, Hoa Phat, which has a market capitalisation of more than $9.6 billion, is Vietnam's largest steel maker with a crude steel production capacity of eight million tonnes a year, according to the company's filing.

(Reporting by Phuong Nguyen; Editing by Ed Davies)