An Edmonton-based forestry company is the latest firm to cancel an agreement to buy electricity from the Sundance C coal-fired power plant.

Millar Western, which operates mills in Whitecourt and Fox Creek, says it expects to record a non-cash writeoff of $21 million.

Capital Power and TransCanada Corporation have previously issued notice that it would terminate power purchase agreements from Sundance plants.

Alberta's NDP government announced in November that it planned to impose a carbon tax and phase out coal-fired power plants in order to reduce carbon dioxide emissions.