BlackRock and BGI are set to merge, creating the world's largest funds house. The figures suggest that the companies will balance each other's strengths, but investment consultants fear that months of uncertainty lie ahead for both the companies and their clients.

The two asset managers are primarily focused on different asset classes and strategies, according to their asset breakdowns at the end of March, when BlackRock managed €802bn ($1.1 trillion), and BGI managed €1.1 trillion.