This had invariably resulted in the companies suddenly having new agendas and new management, with profit becoming their main motivation.
Ms Moore presented a case study of Wellington's local electricity network, which had been sold four times in the past 16 years while its value had quadrupled since 1990.
"The main objective of a succession of private owners has been to maximise profits for their shareholders.
"As a result, electricity line charges have risen steeply, and all the profits made from running the electricity network have flowed out of Wellington, mostly to overseas owners."
Manurewa Local Board member Toa Greening, who appeared before the committee in a personal capacity, said selling the shares would remove the companies from the SOE Act, which "ensures that profit, good employer and social responsibility remains in the forefront of those companies' operations".
"The new mixed ownership company will, over time, change from service, continuity, social responsibility and growth of generation capacity to one of only maximising return," he said.
The companies would also not be able to be held up to public scrutiny through the Ombudsmen Act and Official Information Act should the sales eventuate.
"How will the Government ensure that the companies do not make financially disastrous decisions like performing market manipulations and predatory behaviour?"
Mr Greening also asked how the Government would ensure the mixed ownership companies did not revert to minimal safety practices in an effort to reduce costs and increase profits.
"Pike River mine performed the minimal safety requirements ... Solid Energy goes well above the safety requirements because, as an SOE, it has a focus on the safety aspects of being a good employer and not merely the profit line."
Grey Power spokesman Allen Davies said the sale would benefit large users of electricity, who would get discounts.
"Grey Power concludes that privatisation is primarily for the purpose of this wealth transfer. This purpose has been obscured by the extensive rhetoric, biased analysis, and sheer moneyed interests that have been able to persuade politicians - National and Labour alike - to promote privatisation."