Affiliated Managers Group has said it is in on a drive to buy more alternative investment firms, having just increased its stake in BlueMountain Capital, a hedge fund that reportedly made $30m from betting against JP Morgan’s ‘London Whale’ trades.

The fund manager said in a statement yesterday that it has increased its investment in BlueMountain Capital - a global credit manager that it has owned a minority stake since 2007. It did not disclose the amount for the investment.