The Shamrock consortium comprises utility Kansai Electric Power (Kepco), lender Mitsubishi UFJ Lease and Finance (MUFG) and investment firm Sojitz.
It has acquired the majority share in a portfolio of five wind projects developed by local firm Invis Energy. MUFG said it was the firm's first foreign investment in energy generation.
Four of the sites are in operation and were completed between 2013 and 2017. The four operating projects are: 44.4MW Knocknagoum, 44MW Leitir Guingaid Leitir Peic, 65MW Knockduff, 25MW Killaveenoge.
The fifth project, the 45MW Slievecallan West site, is under construction and due to be completed in early 2018. It will comprise 18 Nordex N90 2.5MW turbines.
Invis will retain a 40% stake in the five projects, which are located in the southwest of Ireland.