Chief executive David Roche said: 'Cathy has played a key role in the management of Borders UK and she will be missed. She has significantly developed the Borders UK offer that we see today.'
Ferrier was director of books at WHSmith and trading director at Poundland before joining Borders in March last year.
Geoff O'Neill will join the group from Woolworths to become the head of supply chain. He will be reporting to finance director Mark Raban, who will take responsibility for supply chain management.
Roche will take over responsibility for the commercial departments while a replacement commercial director is sought.