The European Central Bank has increased the fees it charges banks for supervising them by 21%, reflecting higher costs related to Brexit preparations, it said today. 

The ECB will charge banks €576m this year, up from €475m a year earlier, with the vast majority paid by the largest lenders that are directly supervised by the ECB. 

"The increase in the cost estimate mainly reflects staff increases for banks relocating or growing as a result of the UK's withdrawal from the EU and the corresponding preparatory assessments," the ECB said. 

The increases also reflects higher-than-expected supervision costs last year, which left the ECB's bank supervision arm with a deficit in 2018.