The owners of the Lochaber Smelter near Fort William plan to become the largest provider of renewable energy in the UK.
GFG Alliance has begun the process of acquiring Green Highland Renewables (GHR), which has 18 hydro-electric stations across the Highlands.
The alliance has also proposed constructing eight new hydro-electric plants on land it owns in Lochaber.
It is also currently consulting on plans for a 54-turbine wind farm.
GHR has offices in Perth and Dingwall.
GFG’s acquisition of the company is due to be completed by the end of February next year.
The alliance took over the smelter a year ago. Its purchase includes hydro power plants near the site and at Kinlochleven.
It also involved more than 100,000 acres of land, including Ben Nevis’ foothills.