A move by Countdown, owned by grocery giant Progressive Enterprises, to take the site would presumably be for expansion and would likely mean vacating its present building to relocate to the larger block further south on Queen St.
The land subject to speculation encompasses not only the old Plastalon site - which was used as a community centre in recent years - but the Queen St land once occupied by Dave Anderson Suzuki.
The trust owns the entire block, which includes TRC Toyota and a gym-dance studio.
Mr Sadler said the trust had invited people with an interest in a development to contact its offices and " various people" had been in touch.