Among the three, Chugoku Electric Power Co was hitwith the biggest fine of 70.7 billion yen.
The Japan Fair Trade Commission also ordered Chubu Electric Power Co to pay a 27.6 billion yen fine, while Kyushu Electric Power Co was ordered to pay 2.7 billion yen.
Regulators had investigated the companies foranti-competitive behaviour and concluded that they had formed acartel.
($1 = 132.5100 yen)
(Reporting by Mariko Katsumura; Editing by Christian Schmollinger)