INOX and Henry Boot Developments have formally submitted their enabling plan for the Stadium For Cornwall to planners.
The firms handed in the proposal to Cornwall County Council which focuses on another development at West Langarth featuring a supermarket, shops, housing and community buildings.
Using money from the scheme, the plan is to spend it on bringing the Stadium For Cornwall project to life at Threemilestone, Truro.
The venue would become the new home of the Cornish Pirates.
Their director of rugby Ian Davies said: "This is very encouraging news and supports the desire to achieve a Stadium for Cornwall without cost to the local taxpayer.
“This will be a major infrastructure project not only for Cornwall but for the UK as a whole bringing significant economic benefit to the Duchy."
Pleasure was also expressed by the Stadium For Cornwall group following the enabling plan's submission.
A spokesperson said: "Stadium for Cornwall Group are delighted with the news that the INOX Group and Henry Boot Developments stadium enabling planning application has now been submitted to Cornwall Council.
“The Stadium for Cornwall Group would urge members of the Council to hear this application alongside other supermarket applications currently being considered by the Council in the Truro area.
"This private sector funded community stadium opportunity must not be missed."