Ainsworth is to permanently close one of its three OSB mills in Minnesota.

The Grand Rapids mill, acquired by Ainsworth in 2004 as part of its acquisition of Potlach’s OSB business, has not been in operation since September 2006.

“Given a variety of factors, including our business outlook, the structural challenges of operating in this region, and the condition of the mill at the time it was delivered to us by Potlach, we simply cannot rationalise making the significant investment required to make the mill economically viable,” said chief executive officer Robert Allen.

The mill had 190 employees and an annual capacity of 390 million ft² when operations were suspended two years ago.

Ainsworth said it would continue to have a significant OSB presence in Minnesota throught its plants in Bemidji and Cook, which have a combined capacity of 800 million ft².