CEO Arthur Harris revealed the figure exclusively to The Grocer following the collapse last week of Haldanes Stores and Ruston Retail.
Haldanes issued legal proceedings in the High Court against The Co-op Group, from which it acquired its stores in 2009 and 2010, in May, claiming The Co-op Group "materially breached key terms of the agreements".
At the time it said it had withheld rent from the society, which holds the lease on 17 Haldanes stores, to make it take notice of the allegations. Harris said: "When it became evident that a statement of claim had to be issued for a substantial amount of damages, currently quantified at £7.2m, it would have been madness to pay rent which was substantially less."
The Co-op Group started its own legal proceedings against Haldanes in April "to recover possession of a number of stores" and has said it will vigorously contest Haldanes' legal action.
A number of Haldanes stores are now listed on The Co-operative Group's property website as 'available'.