French infrastructure investor Antin Infrastructure Partners has completed its acquisition of US ship repair and marine services group Vigor Marine Group from an affiliate of Lone Star Fund XI, according to Vigor Marine Group.
The transaction closed on 17 August, six months after Antin agreed to acquire the Portland, Oregon-based company. Financial terms were not disclosed.
Antin plans to expand capacity and upgrade manufacturing equipment and technology across Vigor’s facilities, while developing workforce training programmes. Vigor chief executive Francesco Valente and the company’s US-based management team will remain in place.
Vigor has invested more than $170m in facility improvements and technology upgrades over the past three years while combining five previously separate businesses under one brand. Lone Star’s investment in Vigor dated from June 2023. Lone Star chief executive Donald Quintin called the sale “an important milestone for our partnership with Vigor Marine Group”.
Antin Infrastructure Partners is a French infrastructure-focused private equity firm managing more than €33bn ($38.2bn) across its Flagship, Mid Cap and NextGen strategies. The Vigor acquisition is its seventh investment through Flagship Fund V.
Vigor Marine Group provides marine maintenance, modernisation, fabrication and related services. Vigor operates shipyard and fabrication facilities in Seattle, Portland, Vancouver in Washington state, San Diego and Norfolk, Virginia. The group has six dry docks and 29 berths, employs about 2,700 people and generated more than $1bn in revenue in 2025.