Germany's second biggest banking group Commerzbank said Sunday that its chief executive Martin Blessing had declined to stay on at the helm beyond next year.

"Blessing informed Supervisory Board Chairman Klaus-Peter Mueller today that he will fulfil his contract, which runs until end of October 2016, but he will not accept the offer to extend his term," it said in a statement.

Mueller expressed "deep regret" over Blessing's decision and his "appreciation for the success" the 52-year-old executive achieved.

Blessing said in his own statement that after 15 years on the Commerzbank board, and half that time as chief executive, he was ready to "start a new chapter in my career".

Frankfurt-based Commerzbank was severely hit by the financial crisis, having to be rescued by the state in 2009, and the government still holds a 15 percent stake in the bank.

After thousands of layoffs and a strict cost-cutting drive, it has since managed a successful turnaround.

In August, Commerzbank announced that its second-quarter profits had almost tripled, buoyed by higher revenue and a lower tax bill.

It is due to announce its third quarter results on Monday.