Northern Rock chief executive Gary Hoffman has stepped down from the role and from the Northern Rock board with immediate effect.
Non-executive director Ron Sandler has been appointed executive chairman.
Sandler was originally appointed as executive chairman of the bank when it was nationalised in February 2008.
Hoffman, who announced his departure last week, will take gardening leave from the company until April 30, 2011 before moving to become chief executive of NBNK Investments.
NBNK has committed not to make a bid for Northern Rock for a period of 12 months from November 1.
Hoffman leaves Northern Rock with his contractual entitlement, but no bonus or severance package. He was appointed chief executive of the former Northern Rock business in October 2008.
The bank restructured in January this year to create two separate companies, Northern Rock Asset Management and Northern Rock plc.
Following the restructure, Hoffman became chief executive of Northern Rock and NRAM. He has stepped down as chief executive of NRAM following the establishment of UK Asset Resolution Limited, the new holding company for NRAM and Bradford & Bingley.
Sandler says: “The board recognises the role that Gary has played in the rehabilitation of Northern Rock and thanks him for his significant contribution. I will resume my role as executive chairman for the foreseeable future.”