With its own 10,000km railway network, nine private port terminals and revenue last year that was bigger than the gross domestic product of Bulgaria, Vale appears more like an empire than a company.

The Rio de Janeiro-based miner is the world’s biggest producer of iron ore and one of Brazil’s largest companies. If it were not for Vale’s exports, the Latin American country would have run a trade deficit last year rather than its $20.3bn surplus.

However, the sheer size of Vale has proved to be the company’s biggest challenge. The miner’s American depositary receipts are trading at up to a 30 per cent discount to its peers, partly because of concerns that Brazil’s government will not sit by and let such a strategically important company follow its own path.