Energy firm InfraStrata has completed its purchase of the Belfast shipyard Harland and Wolff.
The shipyard, best known for building the Titanic, was sold to the London-based firm in October.
The completion of the sale followed a £3.3m payment to the administrators BDO.
Harland and Wolff went into administration in August, putting 120 jobs at risk, after its Norwegian parent company collapsed.
InfraStrata is due to make a further £1.45m payment by 30 April 2020.
The company has said that it will initially focus on metal fabrication for its energy projects.
It also wants to build a natural gas storage facility in Islandmagee, County Antrim.
John Wood, interim chairman and chief executive officer, said: "Harland and Wolff is once again open for business.
"This is an important day for InfraStrata, the Harland and Wolff workforce and the region as a whole.
"With the keys now in hand, we will shortly be finalising a number of exciting contracts, as well as discussions with lenders, details of which I look forward to sharing very soon."
Michael Jennings, joint administrator for Harland and Wolff said: "Throughout this process we have been hugely cognisant of not only the international reach and recognition of the iconic Harland and Wolff brand, but also the important role the company has played in Northern Ireland's history.
"Harland and Wolff is part of the fabric of the city of Belfast and we are delighted that it has been saved by InfraStrata."