Both companies have said the move was based on strategic grounds and both of Horizon’s projects remain excellent development options.
Horizon Chief Operating Officer Alan Raymant said: “We are grateful for the support and backing of E.ON and RWE npower since the company was formed in 2009. This has enabled us to bring our projects forward to an advanced stage.
“We are also very pleased to enjoy broad public and political support, in particular from the communities around our sites. This continues to make nuclear new build an attractive proposition in the UK.
“We have made good progress in developing our sites, in particular our lead site at Wylfa, and a strong organisation capable of delivering nuclear new build in the UK.
“We will now focus on consolidating the progress made and working with our shareholders as they investigate the opportunities for new ownership.”