Oomi to acquire Lumme Energia, becoming Finland’s largest electricity seller

Oomi is set to overtake Fortum and Helen as Finland’s largest electricity retailer following its purchase of Lumme Energia from Suur-Savon Sähkö (SSSOY). The deal, announced on Tuesday, will add Lumme Energia’s nearly 350,000 customers to Oomi’s existing base of over 500,000, bringing the total to around 800,000. The acquisition, which requires approval from the Finnish Competition and Consumer Authority, is scheduled to take effect on 1 January 2026.