The Kithaironas wind farm, which was developed by the Spanish firm, is located in Boeotia in central Greece and is made up of 30 Gamesa G52-850kW turbines.
The financial details of the transaction with Eren subsidiary EMV were not revealed.
Gamesa first entered the Greek market in 1999. It has developed 87MW of projects and has a portfolio of 547MW at varying stages of development. Gamesa has also installed 179MW of its turbines on other developers' projects.
Eren said it is currently developing "hundreds of megawatts" of wind farms in Greece.