REGINA - Saskatchewan's government is selling off its stake in a heavy oil upgrader to boost its environmental efforts and is brushing aside suggestions that the move is a pre-election ploy.

The province has sold its 50 per cent interest in NewGrade Energy Inc., a Crown asset in Regina.

Premier Lorne Calvert says about $320 million from the nearly $400-million sale will be used to capitalize a Green Future Fund.

The fund is expected to invest in initiatives to help meet the province's climate change goals, including the development of carbon sequestration and increasing renewable energy.

Calvert says work on the sale began 18 months ago and is not a last-minute selloff in the lead-up to a possible fall election.

He also insists that since the money is being reinvested in a public fund, the sale is different than privatizing publicly owned utilities - something the NDP has accused the Opposition Saskatchewan Party of wanting to do.