This paper investigates the real effects of mandatory climate-related disclosure by financial institutions on the funding of carbon-intensive industries. A French law, which came into force in January 2016 in the aftermath of the Paris Agreement on climate change, provides the authors with a quasi-natural experiment. The new regulation, unique in Europe at that time, requires institutional investors (i.e. insurers, pension funds, and asset management firms), but not banks, to report annually on both their climate-related exposure and climate change mitigation policy. Using a unique dataset of security-level portfolio holdings by each institutional sector in each euro area (EA) country, this paper compares the portfolio choices of French institutional investors with those of French banks and all financial institutions located in other EA countries.