Rio Tinto, one of the world's biggest producers, is the subject of a contested bid by the Australian mining group BHP Billiton, worth about 160 billion dollars at current share prices. The BHP-Rio deal is being scrutinised by antitrust regulators, who fear that, should the bid be allowed to proceed, a combined group would dominate the global supply of important materials such as iron ore and aluminium. Bankers believe Rio's iron ore assets are currently worth about 50 billion dollars. But this figure could fall sharply in the next few months.
Experts believe ArcelorMittal could afford a stake on a par with the 9 per cent stake, worth about $14bn, acquired in February by Aluminium Corporation of China (Chinalco) in combination with Alcoa of the US.
ArcelorMittal declined to comment on market speculation.