Metsä Board will temporarily suspend production at the mills in Simpele, Kyro, Tako and Äänekoski. With this measure the company reacts to the extended strikes at Finnish ports.
Production at these sites will be stopped on Monday 25 March.
It was unclear when the mills could resume production.
"The mills can be restarted as soon as raw material is available and product transportation begins," the company stated.
Production at the Metsä Group's pulp and kraftliner mill in Kemi, the pulp and BCTMP mills in Joutseno and the BCTMP mill in Kaskinen had already been shut down.
The Rauma, Vilppula, Renko and Lappeenranta sawmills have also been affected.
