The English shelf company, which is being investigated by the Flood Tribunal and the Criminal Assests Bureau, came into possession of the lands in 1993.
But the Council's 1990 draft development plan for the motorway put it going through their 106 acre site.
A senior executive with Hamilton Osbourne King, John Morley, valued the Jackson Way lands at €47 million on the basis that they would have been rezoned for residential contruction in the absence of the motorway.
Mr Morley is due to be cross examined by the Council's legal team about why Jackson Way originally put in a claim for more than €114 million but then cut it suddenly by 60%.
The Council argues that the current claim for more than €47 million is excessive.
The hearing is expected to continue for at least another week after which the arbitrator, John Shackleton, will consider his binding recommendation.
