George Soros, billionaire and philanthropist, yesterday bought a $4.6m (€3.6m) stake in an Australian mining company, the latest in a string of large purchases in what he sees as undervalued companies.

Budapest-born Soros who ranks 97th in the Forbes Rich List with $8.8bn to his name, bought a 5% stake in Australia-listed Sphere Investments, which is seeking to develop a $2.1bn iron ore mine in Mauritania.