Last year the Nordic country said it could limit power exports if hydropower reservoirs fell under a certain level, in the first instance of "power protectionism" in Europe, which drew the ire of its Nordic neighbours.

Friday's announcement is a formalisation of what has been in place since last year, officials said.

"We want to ensure there is always enough water in our reservoirs. There should always be enough power in our sockets (at home) and we should have enough power for our industry," Prime Minister Jonas Gahr Stoere told a news conference.

GRAPHIC - Norway hydropower reservoirs

https://www.reuters.com/graphics/NORWAY-POWER/lgvdkldmepo/chart.png

Hydropower accounts for around 90% of Norway's electricity output, much of it depending on power plants fed by water from large reservoirs.

The minority centre-left government is under pressure to lower power bills for households, with the cost of living the main issue of concerns for voters.

GRAPHIC - Norway net exports 2022

https://www.reuters.com/graphics/NORWAY-POWER/zjvqjerkrpx/chart.png

(Reporting by Nora Buli, editing by Gwladys Fouche)