Assets remained unchanged at €227bn (£191bn) or 16 per cent of all money invested in ETFs in Europe.
Morningstar called the drop a "temporary blip in what is routinely heralded as a solid trend in favour of sustainable investing".
But it added: "It seems that investors have found it too difficult to ignore the opportunity to cash in on booming valuations in sectors related to energy and fossil fuels, which are severely underweight or excluded from ESG indexes.
"In fact, flows into equity ESG ETFs totalled €8.4bn, a sharp decline from the €22.5bn netted in the last quarter of 2021.
"Meanwhile, flows into bond ESG ETFs remained broadly unchanged at €4.6bn."
carmen.reichman@ft.com