TORONTO - Ontario's opposition parties warn that the Liberal's plan to sell a majority of Hydro One will drive up electricity rates and reduce government control over the major utility.

Premier Kathleen Wynne insists the government must sell 60 per cent of Hydro One to fund badly needed public transit and infrastructure projects.

The Progressive Conservatives and New Democrats predict electricity rates will "go through the roof" after a Hydro One sale, which they warn will slash future government revenues from the transmission utility.

And they say the government could be out-voted on any Hydro One decisions by the private sector companies who will own 60 per cent of the shares, even though no one owner can hold more than 10 per cent.

But Wynne dismisses the opposition concerns, and says the Ontario Energy Board will still set electricity rates, not Hydro One.

A government-appointed panel that reviewed Crown assets concluded the province could raise $9 billion by selling 60 per cent of Hydro One.