Dong Energy will phase out Unit 3 at Ensted Power Station near Aabenraa and Unit 2 at Stigsnæs Power Station near Skælskør in Denmark.
The planned phasing-out is partly due to the financial crisis and the expected lower future electricity consumption.
The two power stations had jointly emitted just under 2 million tons of CO2 in 2009.
Both units are due to be shut down on 1 January 2013.