The Helsinki-headquartered group is one of the world’s oldest and largest owners of private forests.

It plans to sell around 12% of its huge 1.4m hectares of forest assets in Sweden.

It owns total forest and plantation land spanning some 2.5m hectares.

At the half-year Stora Enso’s net debt increased by €466m (£390m) to nearly €3.5bn, mainly due to the investment in board production and conversion at its Oulu Mill.

The proposed sale will require a new legal structure for its Swedish forest assets in order to facilitate a deal.

“A potential transaction would be subject to agreeing terms and conditions with investors, including a long-term wood supply and forest management agreement,” the group stated.

Stora Enso had sales of €9.4bn last year.

The financial consequences of its recent environmental incident in Finland are not yet known.