Following the merger agreement between Gamesa and Siemens in June, Areva exercised its option to sell its stake in Adwen to Gamesa.
The troubled French firm is looking to consolidate its activities and focus on nuclear generation. "This sale is part of the transformation plan undertaken by Areva to refocus its business on nuclear fuel cycle activities," the company said.
"Commitments made as part of the tender process for offshore wind farms in France will remain borne by Adwen," it added.
Adwen has a 1.5GW pipeline in France and has a commitment to build to factories in Le Havre, northern France.
It is expected the Siemens-Gamesa company, once the merger is completed, will look to sell Adwen on to a third party.