Huntly-headquartered Pipeline Technique has been bought by London-based private-equity firm Blue Water Energy (BWE) in a multi-million pound deal.
Blue Water Energy (BWE) bought the firm from Dutch business Heerema Marine Contractors (HMC).
Duncan McGregor, a welder, and subsea engineer Ian Stuart founded Pipeline Technique in 1998.
HMC initially invested in the firm in 2008 before taking sole ownership in 2015.
Pipeline Technique came back on the market when HMC decided to shut down its offshore pipe-lay activities last year.
The firm employs nearly 100 people and had a turnover of more than £45m in 2017.
BWE already has a north-east presence with investments in Siccar Point Energy, Rovop and Survivex.