Aino Järnroos

Senior Associate, Master of Laws

Services

  1. Private M&A

I advise our clients on assignments related to domestic and cross-border mergers and acquisitions.

During my studies, I specialised in transactions and related subjects alongside general corporate law. I joined Castrén & Snellman as a trainee already before my graduation and was appointed as an associate upon my graduation in 2021. I have also gained valuable experience working in Sweden for a major Nordic law firm prior to my graduation.

I have a Master of Laws degree from Stockholm University. In addition, I have spent an academic semester studying law at the University of Helsinki as part of my master’s studies. I am fluent in three languages and due to my Swedish background and language skills, I have a good understanding of the Nordic market.

Latest references

We advised Topfoods Oy, a Triton-backed Geia Group company, on its acquisition of Oy Delice Plus Ab, a Finnish supplier of cakes and pastries. Through the acquisition, Topfoods strengthens its retail business and further reinforces its position in the cakes and pastries segment. Founded in 2008, Topfoods supplies selected food products to professional kitchens, the retail sector, and the food industry. 
Case published 4.9.2026
We advised HANZA on the divestment of its Nivala and Sievi operations. The transaction was part of HANZA’s larger strategic reorganisation, where the company optimised its Finnish manufacturing cluster. Founded in 2008, HANZA is a Swedish mechanical engineering and electronics contract manufacturing company listed on the Nasdaq Stockholm main list. HANZA has approximately 5,000 employees and annual sales of SEK 10 billion. 
Case published 3.9.2026
We advised Gasum when it acquired 100% of the shares in NSR Biogas AB and the remaining 1/3 of the shares in Liquidgas Biofuels Genesis AB. Gasum has already been the majority owner of Liquidgas Biofuels Genesis AB since 2023 and is now acquiring full ownership. Gasum is a Nordic gas sector and energy market expert. Gasum offers cleaner energy and energy market expert services for industry and for combined heat and power production as well as cleaner fuel solutions for road and maritime transport. The company helps its customers to reduce their own carbon footprint as well as that of their customers.
Case published 5.6.2025
We acted as Finnish advisor to Hanza AB relating to its acquisition of all the shares in Leden Group Oy. Hanza AB is a Swedish mechanical engineering and electronics contract manufacturing company listed on the Stockholm Stock Exchange. Founded in 2008, the company has six manufacturing clusters in Sweden, Finland, Germany, Baltics, Central Europe and China and an annual turnover of approximately SEK 4.6 billion. Leden Group is a leading Finnish contract manufacturer specialising in sheet metal, machining and complex assembly. Leden Group has four production sites in Finland and one in Estonia and an annual turnover of approximately SEK 1.1 billion. 
Case published 13.12.2024
We advised WithSecure Oyj in the sale of its open source data collection product and business to Patria Oyj. The divested business combining software and services falls outside WithSecure’s current strategy. Through the sale, WithSecure sharpens its focus on the Elements portfolio. WithSecure is a global cyber security company (listed on NASDAQ OMX Helsinki) with more than 35 years of industry experience. WithSecure offers partners flexible commercial models, ensuring mutual success across the dynamic cyber security landscape. Patria is an international company in the defence and security industry offering defence, security and aviation life cycle support services and technology solutions. As a result of the transaction, Patria will open a new office in Oulu and 10 WithSecure experts currently working in the business area will join Patria. 
Case published 30.9.2024
We acted as the lead counsel to Fortum in a cross-border transaction in which Fortum sold its recycling and waste business. The business was sold to thematic impact investing firm Summa Equity through its portfolio company NG Group. The debt-free purchase price is approximately EUR 800 million.  Fortum’s recycling and waste business to be sold comprises municipal and industrial waste management and end-to-end plastics, metals, ash, slag and hazardous waste treatment and recycling services. These businesses are located in Finland, Sweden, Denmark and Norway and currently employ approximately 900 employees.
Case published 18.7.2024
We are acting as Finnish legal advisor to Prevas Aktiebolag in its acquisition of approximately 92 percent of the shares in NMAC Group Oy (‘Enmac’). This acquisition marks Prevas’ entry into the Finnish market and is aligned with its growth strategy, enabling future market synergies. Swedish Advokatfirman Lindahl KB is acting as lead legal counsel to Prevas Aktiebolag in this deal. Enmac was founded in 1983 and is a prominent player in the Finnish market offering advanced services in production process development, including advanced technical calculations, industrial automation, product development, as well as process and piping design. With approximately 200 employees and 8 locations in Finland, Enmac achieved a turnover of MEUR 23 in 2023. The transaction is subject to approval from the Finnish Ministry of Economic Affairs and Employment.
Case published 23.5.2024
We advised A. Ahlström Corporation in its acquisition of the majority of Metsäkonepalvelu Oy.  This acquisition further strengthens A. Ahlström’s strategic core sector built around forest and fibre companies. A. Ahlström is a family-owned investment company with core investments in the forest and fibre segment. Metsäkonepalvelu offers mechanical timber harvesting services in Finland and Sweden and is a Nordic market leader. The Company’s customers include large companies in the forestry industry, large private forest owners and the public sector.
Case published 20.12.2023

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