Helmut Siekmann sound a note of caution to EZB banking supervision (Bloomberg)

After the EU General Court has overturned a decision of the ECB banking supervision, Helmut Siekmann has sounded a note of caution. The ECB's banking supervision should avoid taking more decisions that land in court, "because that's the kind of thing that can end up scratching your reputation," Helmut Siekmann said in an interview with Bloomberg.

However, Siekmann does not expect a wave of lawsuits coming at the ECB now. "Banks think long and hard before they sue a supervisor they're in such close contact with". 

Six French banks had won a European Union court fight against the European Central Bank's refusal to change the way it calculates the leverage ratio. 

Bloomberg: ECB suffers setback as French banks win leverage ratio clash.