One line at the two-line mill will operate on a reduced schedule starting on Sept. 5.
Mill was shutdown July 10 to comply with evacuation orders caused by raging wildfires in the area.
More than 8,500 people in BC have been ordered to leave their homes due to the wildfires.
Brookfield Asset Management, a majority shareholder in each company, will own 53% of the combined firm.
Lower prices for OSB blamed for the drop.