Civil engineering and groundworks contractor Tonic Construction Ltd has signed over 80 percent ownership of the company to its 160 employees, via an Employee Owned Trust.
The move will be funded from the Swindon company's future profits.
The company will continue under the same leadership team, led by chairman Tony Iles, who founded the business in 1999, and his wife Debby.
The employee-owned trustee board will include Tony and two employees appointed by the wider team.
"This is a really exciting move for Tonic Construction, enabling us to realise our ambition to become a trans-generational business and guarantee intercompany loyalty and succession," said Tony.
"The collective ownership by all the team secures the future of the business and our core values, meaning we can long outlast the founders and senior team without the threat of a takeover or sale that could result in a dramatic change in business culture.
"This will preserve our valuable long-term relationships, which sit at the heart of everything we do.
Tony said that an Employee Owned Trust model is probably the fairest and strongest business model in current times, and should become the lifeblood of business in all sectors.
Tonic Construction was advised by Manchester-based Fieldfisher, an expert on on employee buy-outs.
Corporate partner Mary Erb said: "It was a pleasure to work for Tonic Construction and we congratulate the firm on its transition towards becoming employee owned. Our thanks also go to BDO LLP for referring Tonic to us."
"By widening ownership of the business, Tonic Construction is sure to secure the future of its business and ethos."