Oranje-Nassau Energie (ONE) is a private Dutch exploration and production company, with a long track record in running a diversified upstream portfolio. Following the acquisition of Dutch operator Cirrus, the acquisition of NAM's operated Q16 field and most recently the Shell UK operated Sean gas field, ONE focuses on expanding its North Sea operated portfolio and will also look at attractive investment opportunities West of Africa. In the past ONE only focused on non-operated North Sea ventures (the Netherlands and the United Kingdom) and was able to successfully grow, diversify and renew its reserve base over the last 30 years.
Following a strategic review of its activities, Oranje-Nassau Groep, the former parent company of ONE, decided to divest its energy business end 2008. In May 2009 the divestment of ONE to a consortium consisting of ONH B.V. (a private Dutch investment company controlled by Marcel van Poecke), Dyas UK Limited and Sumitomo Corporation was completed. ONH B.V. retained ONE with its management team and acquired the Dutch and Gabon assets, plus a minority stake in the offshore UK Buzzard oil field.