"The board has received four substantive proposals regarding the future of the company, including the Augusta proposal, and has commissioned Northington Partners to undertake an independent assessment of each of these," NPT said.
"To allow sufficient time for this and, acknowledging the impact of the Christmas break, the board considers that the proposed timetable is fair and reasonable and its external advice supports this," NPT's statement said.
John Anderson, NPT chairman, said Augusta was "trying to play a fast game in an attempt to hurry the process in its own interests."
The board remained open to Augusta's proposal and wanted to assess that proposal and all others through a robust process, Anderson said. NPT shareholders would be kept regularly updated, he said.