A partial outage at Sweden's Forsmark 2 nuclear reactor was extended by three weeks until Jan. 24 while repairs are made to a generator, the operator said in a market message posted via Nordic power exchange Nord Pool on Wednesday.

Forsmark Block 2 will operate at just 490 megawatt (MW) of its total 1,121 MW capacity, the note said.

The outage coincides with a winter cold snap that has sent Nordic temperatures to their lowest levels in decades, boosting demand for electricity in heating. (Reporting by Terje Solsvik, editing by Nora Buli)