He starts on 9 January 2012, when interim chairman Sir Michael Lyons will step back into his role as senior independent director.
Mr Shearer is an experienced board director and turnaround specialist. He led the restructuring of Crest Nicholson in 2008/9 as chairman and of City Inn in 2010/11 as chief strategic adviser. He was also involved as a non-executive director in the turnaround and refinancing of Renold, STV Group and Superglass Holdings.
He is currently deputy chairman of Aberdeen New Dawn Investment Trust, senior independent director of Martin Currie ( Holdings), Renold, STV Group and Superglass Holdings. He is also a non-executive director of Mithras Investment Trust and was, until 2007, a non-executive director of HBOS.
Sir Michael Lyons said: "David's extensive experience of turnaround and capital restructuring situations was a key factor in his appointment and his appointment is good news for everyone who has an interest in the early recovery of Mouchel."
Mr Shearer said he looked forward to helping bring about Mouchel’s recovery.