Deal Announcement: Oomi completes acquisition of the business operations of Lumme Energia

Type of deal: Electricity Retail and Energy Services

Sector: Electricity Retail and Energy Services

Oomi Oy (Finnish energy services company) acquired the business operations of Lumme Energia Oy (the electricity retail arm of Suur-Savon Sähkö) in a transaction merging Lumme’s entire electricity sales business into Oomi. The deal was publicly announced in mid-August 2025 and, after receiving Finnish Competition Authority approval in September 2025, was completed on 1 January 2026 (Day 1 of integration). This combination created Finland’s largest electricity retailer – for a total of about 800,000 customers nationwide. As part of the deal structure, Lumme Energia’s owner, Suur-Savon Sähkö Oy, became a minority shareholder (20.8%) in Oomi Oy, while the Lumme Energia brand will be phased out as operations consolidate under the Oomi brand during 2026. Existing customer contracts of both Oomi and Lumme Energia were unaffected by the merger (no changes to terms or pricing for customers).

Object of sale: Lumme Energia’s entire electricity retail business operations (all of Lumme’s electricity sales customers, contracts, and related business assets

Seller: Lumme Energia Oy

Buyer: Oomi Oy

Deal announcement date: 13 August 2025 (public announcement of Oomi–Lumme transaction). Deal completion: 1 January 2026.

PwC’s role: PwC acted as Oomi’s and Lumme Energia's joint advisor for the valuation, integration and transformation, providing comprehensive support throughout the deal and post-merger integration process.

PwC’s multi-disciplinary team assisted in the early phases of the deal by providing deal negotiations and valuation support, financial due diligence, transaction structuring and in post-signing phase traditional integration planning and Day 1 readiness activities, while also co-developing the combined company’s new strategy and business plan, facilitating the design of the future operating model, organizational structure, and culture for the merged entity. The team supported synergy identification and value capture planning, advised on technology platform selection and integration roadmap, and ensured regulatory compliance by providing competition law guidance and employment law support during the process.

This end-to-end approach helped deliver a seamless transition on Day 1 and positioned the merged company for its strategic growth objectives.

Press release