FRANKFURT: The European Central Bank plans to increase scrutiny of bank board directors and will take look more closely at diversity within management bodies, ECB supervisor Edouard Fernandez-Bollo said on Friday.

The ECB already examines the suitability of board candidates in a so-called fit and proper assessment, but rules across the 19 euro zone members vary, so the quality of these checks can be inconsistent.

The ECB plans to ask banks to undertake a suitability assessment before making appointments, and they will put greater emphasis on the candidates' previous positions and the bank's specific needs, Fernandez-Bollo said in a speech.

The supervisor also plans more detailed rules on how it will reassess board members once new information emerges, particularly in case of breaches related to anti-money laundering and financing of terrorism, Fernandez-Bollo added.

Fernandez-Bollo did not talk about enforcing diversity quotas, but he argued that diversity, including diversity in gender, backgrounds and experiences, improves efficiency and was thus crucial.

"Supervisors will consider furthermore all of the diversity-related aspects that are most relevant to enhancing the individual and collective leadership of boards," he said.

"Diversity within a management body is therefore crucial ... there is a lot of room for improvement in this area in European banks," he said.