The ownership structure of Subsea 7 features a combination of prominent institutional asset management firms, strategic corporate entities, and public market investors. The single largest controlling shareholder is Siem Industries S.A., which holds a major significant equity stake in the company. Other substantial institutional shareholders registered on the company's shareholder register include major financial institutions and investment funds such as Folketrygdfondet, Elliott Management Corporation, BlackRock Institutional Trust, Vanguard Capital Management, and various Scandinavian asset management firms that provide broad market liquidity and professional governance oversight.