Annan, a director with convenience retail consultants Srcg, said this change needed to take place irrespective of whether the group remained mutual or rekindled its deal with Costcutter.
He predicted that the number of large symbol retailers would be slashed over the next four years. He said: "There are currently six or seven large symbol retailers in the UK. By 2010 this will have reduced to just three really strong consumer brands with a clear consumer promise.
He suggested that Nisa members could protect their independence with a "Nisa at" fascia under which all the members could unite. He added: "Nisa is a trading group which pretty quickly needs to become a retail group."