Areva announced it will buy the remaining stake in Multibrid, to be renamed Areva Wind, from developer Prokon Nord.
Prokon Nord sold the first 51% to Areva three years ago for about €150 million.
Six of Multibrid's 5MW, offshore-specific turbines are in a testing phase at the Alpha Ventus project in the North Sea.
Areva recently announced plans to build some of the machines in the US, most likely before 2014.
The hybrid between a multi-stage gearbox turbine and a direct-drive turbine with no gearbox was originally designed by German firm Aerodyne.
Areva Renewables chief executive Anil Srivastava said: "As major utilities are moving ahead by launching a number of European tenders, this acquisition illustrates AREVA's commitment to play a leading role in the development of the offshore wind industry and to establish long-term partnerships with customers."