Schroders is the latest big-name asset manager to launch a new infrastructure debt fund — and an increasingly crowded market has encouraged it to venture into higher-risk lending to smaller companies than investment firms usually do.

Funds raised to lend money to infrastructure projects, like utilities, toll roads, power plants and railways, have pulled in a combined $43bn since 2009, according to data provider Preqin. 2017 is set to be a record year and some of the largest-ever funds have closed in the past few months, including a $5.7bn blockbuster raised by BlackRock in July.