This has enabled Rio Tinto to take swift control of the diversified miner, announcing that it had gained 54.25% of the stock in morning trade and allowing it to automatically extend its offer to August 25.

Arbitragers had bid the stock up to $5 last week on speculation that Anglo American would trump Rio’s $4.75 bid for the company.

North shareholders earlier missed out on a piece of its $424.5 million profit when it declined to offer a dividend.

Morgan Stanley has said that it will drop North from its MSC index - used as a guide for institutional investors around the world as to how they should invest in each country - after August 14.