The proposals, which include creating new native woodland as well as forestry plantations in the Glen Dye area, represent the biggest natural capital project to be announced in Scotland since COP26, according to the buyers.
The site, which includes the prominent hilltop of Clachnaben, is popular with walkers and outdoors enthusiasts from the local area and further afield.
The firms behind the project, Aviva Investors and Par Equity, estimate the work will lock up 1.4 million tonnes of climate-warming carbon.
Following public and statutory consultation, applications will be made to undertake extensive peatland restoration work across around 1,800 hectares of the land as well as new planting over 3,000 hectares.
Around a third of the trees planted will be commercial conifers and the rest native woodland, including pine and broadleaf species.
The project will be designed, implemented and managed by forestry company Scottish Woodlands and undertaken over five years.
It will bring “significant employment opportunities” as well as enhancing public access and facilities, the owners say.
It is also expected to make a substantial contribution to Scottish and UK forestry planting targets.
The announcement comes just weeks after an estimated eight million trees were blown down during storms Arwen and Barra.
Daniel McHugh, chief investment officer of Real Assets at Aviva Investors, said: “The intention is for our carbon-removal programme to be considered a best-in-class initiative, which not only sequesters a vast amount of carbon over its lifetime, but does so in a way that takes into account the surrounding habitats and community.
“In the case of Glen Dye moor, we will do this while maintaining and improving the network of access trails, enhancing biodiversity and restoring the degraded peatland across the land.”
Tom Croy, investment manager at Par Equity, said: “The acquisition of land at Glen Dye offers a tremendous opportunity to deliver an outstanding project as part of the journey to net zero.
“It will make a major contribution in terms of carbon capture and peatland restoration at national scale and will also provide employment while protecting and enhancing the landscape for the enjoyment of the many people who live in and visit the area.”