The value of the Ontario government's signature green energy deal with Samsung has been slashed by $3.7 billion as the province reduces the amount of electricity it will buy from the South Korean company.

Energy Minister Bob Chiarelli says the province will spend $6 billion to buy electricity produced by Samsung's wind and solar projects, down from $9.7 billion in the original 2010 agreement.

Chiarelli says Samsung missed some deadlines so the province was able to re-open negotiations and reduce the amount of electricity it will buy from 2,500 megawatts to 1,369 MW.

Samsung's original commitment to invest $7 billion in new manufacturing plants for green energy components as well as wind and solar power projects has been reduced to $5 billion under the renegotiated deal.

Ontario has renegotiated the deal before, cutting $327 million from a $437-million incentive over 20 years that it initially agreed to.

Chiarelli was unable to say how much Ontario would pay Samsung for each kilowatt hour of electricity produced by the six wind farms and solar projects it's building in the province.

The opposition parties say the Liberals' green energy policies are a "complete disaster" and have driven electricity prices in Ontario through the roof.