London (CNN Business) The layoffs have started at Deutsche Bank as the struggling lender embarks on a dramatic overhaul that will reduce its workforce by 18,000.

CEO Christian Sewing confirmed during a conference call that layoffs had started Monday in Asia. He said Deutsche Bank teams in other parts of the world would also be affected.

Sewing unveiled a restructuring on Sunday that will eliminate roughly one in five jobs at the German bank.

"I am very much aware that in rebuilding our bank, we are making deep cuts," the CEO said in a letter to employees. "I personally greatly regret the impact this will have on some of you."

Deutsche Bank has not given details on which offices will bear the brunt of the downsizing. The bank has said its workforce will shrink to roughly 74,000 employees by 2022.

Read More