The new owners of the UK's last aluminium smelter plan to make vehicle components on the site in a move that could create hundreds of jobs.
Companies created by GFG Alliance took over the running of the Lochaber Smelter near Fort William last year.
The new project would involve the creation of a steel rolling mill and facilities for making components such as alloy wheels.
It could add 600 jobs to the 170 already involved with the yard.
The auto-components manufacturing plant forms "the centrepiece" of a planned £120m first phase of longer term investment in the smelter that could eventually run to an estimated £450m.
'Greenest metal production'
GFG Alliance companies Liberty British Steel and Simec Lochaber Power said phase one could create a mix of up to 600 new direct and indirect jobs.
Longer term, the firms said production at the site could support 1,000 direct and 1,000 indirect jobs and add £1bn to the Scottish economy.
The overall investment would include the construction of housing and other services for workers.
Aluminium currently made at the smelter, which lies in the foothills of Ben Nevis, is taken elsewhere to be made into various products.
The announcement of phase one of the investment programme followed the first meeting of the Lochaber Delivery Group.
Liberty and Simec set up the delivery group with the Scottish government and public agencies, including Highlands and Islands Enterprise, to support the programme.
Following Friday morning's meeting, Rural Economy Minister Fergus Ewing formally switched on newly-installed bio-diesel generating units located within a hydro-power station adjacent to the smelter.
The units will make the smelter "the greenest metal producing facility in the UK", according to the site's owners.
About £10m is being invested in the hydro scheme and bio-diesel units. They are expected to reduce the need to import electricity to the site.
The new units form one of the first steps towards the creation of the planned new manufacturing plant.
'Exciting new chapter'
Sanjeev Gupta, executive chairman of the GFG Alliance said after the first meeting of the delivery group: "I am delighted to report excellent progress in our work programme with partners in Scottish government and local agencies.
"One of the reasons we invested in the Highlands was because people welcomed us here.
"That's been reinforced by the positive response of the many agencies in the new Lochaber Delivery Group who showed today that they are eager to play their part in delivering the goal of a clean, competitive and sustainable manufacturing sector in the Highlands."
Mr Ewing said an "exciting new chapter in the history of the local area" was beginning.
He said: "Through the Lochaber Delivery Group we look forward to continuing to work with them to facilitate and maximise the opportunity their investments will bring.
"That includes planning for housing and associated services, the construction of the new factory and the right training provision for workers."
Mr Ewing added: "The UK's last remaining aluminium smelter will continue as a key component of Scotland's industrial capability and a major source of employment in the Highlands and Islands, and the planned factory promises further expansion and opportunity for communities in Lochaber and beyond."
GFG Alliance took over the smelter from Rio Tinto in a £330m deal last year, which was welcomed by First Minister Nicola Sturgeon on a visit to the site in December.
About 170 people are employed at the smelter, making it one of the largest employers in Lochaber.
The GFG Alliance companies have already submitted a pre-planning application document with Highland Council for the proposed manufacturing plant.