The chief executive of BlackRock has written to bosses of some of the world’s largest public companies, demanding an overhaul in how they interact with shareholders and urging them to engage in discussions with activist investors at a much earlier stage.

In a letter to company bosses, Larry Fink, who co-founded the $6.3tn asset manager in 1988, said: "The time has come for a new model of shareholder engagement — one that strengthens and deepens communication between shareholders and the companies that they own."