Administrators have confirmed the sale of Ferguson Shipbuilders in Inverclyde to businessman Jim McColl's firm, Clyde Blowers Capital.
The company had been chosen by KPMG as preferred bidders last month.
Ferguson, which went into administration with the loss of 70 jobs, will be renamed Ferguson Marine Engineering.
Mr McColl has promised to upgrade facilities at the Port Glasgow yard and seek work in the renewables sector.
He also hopes to grow the workforce from its pre-administration level of 77 to 120 people.
Joint administrator Blair Nimmo said: "It is extremely pleasing to secure the sale of Ferguson Shipbuilders in such a short timeframe and to buyers who can see the potential in the business and its skilled workforce.
"We would like to thank those employees, and all parties with an interest in Ferguson Shipbuilders, including various government agencies, for their patience and support during this period.
"We would also like to wish Clyde Blowers Capital every success for the future.
"As new owners they have an ambitious vision to build on its heritage and grow a successful shipbuilding and marine engineering business on the Clyde."
Mr McColl said: "We are pleased to have completed the purchase of Ferguson's and are excited by its potential to grow into a leading marine engineering business."
He added: "Work is now well underway to develop a plan to rebuild Ferguson's, and we look forward to working with the key stakeholders in that rebuilding process."