BlackRock’s $10tn asset management empire is built around passive index investing. Chief executive Larry Fink is betting that infrastructure will help drive his firm’s next wave of growth.

The money manager agreed in early January to buy Global Infrastructure Partners for $12.5bn, its biggest push yet into what are known as private market investments that don’t trade on a public exchange. GIP, a New York-based infrastructure fund manager with roughly $100bn in assets, owns and operates energy, transportation, and waste and water companies around the world.