"Those sort of talks haven't even been held yet."
But he said iwi should be allowed to invest in Air NZ and the energy companies.
"For those particular companies, iwi have shown interest and that's a form of saving and we need to save in New Zealand.
"If they want to do that, we would support them to invest in that."
Mana Party leader Hone Harawira, who quit the Maori Party earlier this year over its relationship with National, was staunchly opposed to the policy.
"New Zealanders should absolutely be in charge of our core services, in terms of housing, in terms of water, in terms of electricity."
He said the private sector would make the companies worse.
"Ordinary New Zealanders care, because we already bloody own them ... Why on earth are we selling assets that we already own back to ourselves? There's something seriously wrong with that policy."
The comments highlight differences between the parties and emphasise one of the reasons why Mr Harawira quit the Maori Party - because he said the Maori Party were working for corporate Maori and iwi, at the expense of everyday Maori.
Other minor parties were divided on the issue.
Greens co-leader Metiria Turei said it would be irresponsible to sell shares in New Zealand-owned companies to invest in schools and hospitals.
"If we're going to pay for health and education, we need to have a sustainable economy that can do that in the long-term, and not sell off our state-owned assets to pay for it in the short-term."
Act leader Don Brash, who supports selling state owned assets wholly, said: "Does anyone seriously believe that a Government runs a business better than private owners do? No one seriously believes that."
Differences between the Mana and Maori parties also emerged over benefit payments, with Dr Sharples in favour of welfare reform, and Mr Harawira supporting boosting benefit payments.
Mr Harawira supported free breakfast and lunches in schools, but Dr Sharples did not, saying the country needed policies to lift poor households so they could pay for their own meals.
Mr Harawira made an embarrassing gaffe when he said the money that saw New Zealand's continued military presence in Vietnam should go towards alleviating child poverty.
He meant to say Afghanistan.
Dr Sharples also said the party was against cannabis decriminalisation, while Mr Harawira said he was happy to consider it.