Not-for-profit foundations have for the first time become the most common type of investors in private equity, according to the latest analysis of institutions that back the asset class.

A total of 710 foundations - organisations with a philanthropic purpose - now invest with private equity, making up 15% of all investors in the industry globally, according to data provider Preqin. This is up from 489 foundations last year, when they comprised 13% of all investors and 11% in 2011.