The Department of Conservation is investigating whether Contact Energy land along the Clutha River could be owned in a partnership.
Botanists have identified more than 100ha of land with rare and endangered plant species. The government-funded Nature Heritage Fund is negotiating with Contact to buy the land on Doc's behalf.
The company on Monday rejected a call by a group led by Emeritus Prof Alan Mark to gift the land to Doc.
The possibility of a partnership was raised in an email exchange between Sir Alan and Doc director-general Lou Sanson.
Mr Sanson asked one of his staff to look at the issue ''from a partnership perspective''. Until his staff had completed their work, he was not in a position to comment, he said.
Sir Alan yesterday provided more information on the land.
''Almost all of the areas support some threatened or at-risk plant species. Some of the areas are of glacial outwash landforms which are classified nationally as naturally uncommon ecosystem types.''
There were also some small wetland areas considered to have become ''uncommon''.
