The European Central Bank has extended a deadline for filling three top jobs at its bank supervision arm after it failed to hire any women for the roles, two sources said, illustrating the bank's long struggle to attract female talent for senior positions.

With only one woman on its 25-member Governing Council and just a handful of women on the Supervisory Board, the ECB has long been criticized by European lawmakers for fostering a culture that favors men, with males holding over three quarters of senior managerial positions.

Pressure on the bank only increased in recent months when the top two bank supervisors, Daniele Nouy and Sabine Lautenschlaeger, were replaced by men, seemingly countering the ECB's stated goal of improving its gender balance.