The world’s largest investor, Japan's  sprawling Government Pension Investment Fund, has set out the details of its radical new fee structure for external fund managers — after concluding their performance “leaves much to be desired”.

The $1.46tn pension fund has been reviewing the way it pays its stock-pickers, who manage around 20% of the pension scheme's money, since last summer. Only a “small number” of its active managers hit their performance targets between 2014 and 2016, GPIF said.