Additionally, he has left his position on the board with immediate effect, leaving 10 members at the table.
Deputy chief financial officer Marc Jenkins will take on Arden’s role while the bank looks for an interim chief financial officer, a process it says has already begun.
Arden joined Metro in early 2018 after a six year stint as Sainsbury’s Bank chief financial officer.
The lender will be issuing preliminary financial results next Wednesday, 23 February
Metro chief executive Daniel Frumkin says: “On behalf of the Board I would like to thank David for the important work that he has done to strengthen Metro Bank’s financial controls over the past two years.
“He has played an instrumental role in helping to deliver the bank’s strategic priorities and turnaround plan and leaves with our best wishes for the future.”
At the end of last year, the Bank of England’s Prudential Regulation Authority fined Metro £5.4m for failures made in its reporting duty.