A Crown lawyer has suggested in the Supreme Court that time limits on shareholdings in state hydro-electric power companies would be a way to safeguard Maori water rights.
The two-day appeal hearing led by water claimants ended on Friday with the Crown's legal counsel delivering its argument.
Claimants want the Government to deal with Maori interest in freshwater before it proceeds with share sales in power stations this year beginning with Mighty River Power.
One debate raised in the Supreme Court has been the prospect of Maori interests in water rights being impaired by the transfer of shares.
The Crown's lawyer, David Goddard, QC, provided a suggestion to counter that in the event that shares are sold to the public.
He said one idea would be for shareholders not to have any further rights after 35 years.
Mr Goddard also said that under a current resource consent review it is possible that there could be changes to the management and the use of water.
The Supreme Court has reserved its decision on Friday.