Unicredit CEO Federico Ghizzoni has agreed to resign following days of speculation about his future amid investor discontent over the performance of Italy's largest bank.

The bank said in a statement after an extraordinary board meeting Tuesday that Ghizzoni would remain in his post until a successor is named, adding simply that "conditions are ripe for a change in top management."

The bank's shares have dropped by nearly 40 percent this year amid concerns over its weak capital position and low profitability.

Ghizzoni's nearly six-year tenure spanned the sovereign debt crisis and Italian recession, and has been marked recently by cost-cutting and moves to shrink its impaired loans.

Unicredit shares closed up 4.87 percent at 3.06 euros ($3.43) in anticipation of the board meeting.