Timber companies and environment groups have unveiled an agreement aimed at protecting two-thirds of Canada's vast forests from unsustainable logging.
Over 72 million hectares are included in what will become the world's largest commercial forest conservation deal.
Logging will be totally banned on some of the land, in the hope of sustaining endangered caribou populations.
Timber companies hope the deal will bring commercial gains, as timber buyers seek higher ethical standards.
The total protected area is about twice the size of Germany, and equals the area of forest lost globally between 1990 and 2005.
"The importance of this agreement cannot be overstated," said Avrim Lazar, president and CEO of the Forest Products Association of Canada (FPAC).
"Together we have identified a more intelligent, productive way to manage economic and environmental challenges in the Boreal [Forest] that will reassure global buyers of our products' sustainability."
The Canadian Boreal Forest Agreement (CBFA) brings together FPAC's 21 member companies and nine environment groups, many of which have fought a bitter battle against what they have sometimes criticised as rapacious logging.
As part of the agreement, those groups have agreed to suspend criticism of the industry and calls for boycotts.
The Pew Environment Group, which has worked for about a decade on trying to "green" Canada's forestry, said it was "excited" by the agreement.
"We're thrilled that this effort has led to the largest commercial forest conservation plan in history, which could not have happened without both sides looking beyond their differences," said Steve Kallick, director of Pew's International Boreal Conservation Campaign.
Pew notes that the total area covered by the deal is larger than in some agreements currently feted as global leaders, such as the Brazilian Amazon Region Protected Areas project.
Throughout the protected lands - which run right across the country from the Pacific to the Atlantic coasts - companies and environment groups are pledging to work together to implement "world-leading forest management and harvesting practices".
The effects of forest protection on wildlife, particularly caribou, will be monitored; and timber will be certified as coming from sustainable sources.
Pew believes the agreement could be a template for future forest agreements in other parts of the world, as industry leaders respond to an increasingly environmentally-aware public.
"There is a recognition that this is how forestry will be done in the 21st Century, and there's a great interest in getting ahead of the rest of the industry," Mr Kallick told BBC News.
The agreement at present covers companies and environment groups; both parties are looking now for backing and re-inforcement from governments.
In the Canadian system, that means the national and provincial authorities, and "First Nation" governments of indigenous groups, some of which have already indicated their support.