Noora Ahonen

Senior Associate, Member of the Finnish Bar, M.Sc. (Econ.)

I advise our clients on a wide array of domestic and international tax matters. I joined Castrén & Snellman in 2021. Before joining Castrén & Snellman, I worked, among other things, as a tax specialist in the Finnish Tax Administration, as a judge of the administrative court, as tax consultant for a major auditing firm and as a lawyer at another Finnish law firm. I have, therefore, worked with a wide range of tax matters concerning both private persons as well as domestic and international organisations and gained valuable experience in handling tax matters in the Finnish Tax Administration and in the administrative courts.

In addition to my law degree, I hold a Master of Science in Economics. I have also completed court training, i.e. I have appointed as a lawyer trained on the bench.

Latest references

We advised UK-based investment company Downing in its acquisition of the entire share capital of Tornionlaakson Voima Oy. Tornionlaakson Voima owns three hydropower plants in the Tengeliönjoki river system – the Portimokoski power plants in Ylitornio, the Jolmankoski power plants in Raanujärvi and the Kaaranneskoski power plants in Sirkkakoski. The power plants produce a total of approx. 45 gigawatt-hours of electricity per year. Tornionlaakson Voima’s daily operations will continue normally, and the transaction will not affect customers. The consummation of the transaction is subject to the approval of the Ministry of Economic Affairs and Employment. Downing has over 35 years’ experience in providing a wide range of investment solutions to the needs of institutional investors, advisers and retail investors. The company manages over £2 billion in assets in both the private and public markets and its current hydro power portfolio includes approx. 50 hydro power plants in the Nordics. 
Case published 27.3.2026
We are acting as the joint legal advisor to Oomi Oy and Lumme Energia Oy in a transaction whereby Lumme Energia will merge with Oomi. As from the completion of the merger, the combined entity will be the largest electricity retail and service company in the Finnish market. In 2024, Oomi reported a turnover of EUR 373.9 million and had approximately 110 employees. Lumme Energia’s turnover for the same year was approximately EUR 314.6 million and it had approximately 50 employees. The transaction is primarily driven by the recent developments in the electricity market and the strategic goal to develop competitive products and services. Another key objective is to further enhance the customer experience, which is a shared value between the two companies. As a result of the merger, Lumme Energia’s customers will transfer to Oomi, and Lumme Energia will become one of Oomi’s shareholders. The completion of the transaction is subject to an approval by the Finnish Competition and Consumer Authority.
Case published 29.8.2025
We advised Jefferies as the sole arranger and lead manager in a transaction in which Finnfund, a Finnish development financier and impact investor, issued a EUR 100 million green bond. The 10-year bond bears interest at the rate of 3.5% per annum. The bond offering was placed to international investors, including a portion of dedicated green bond investors/portfolios. The bond represents Finnfund’s first ever green transaction and second issuance under its Sustainability Bond Framework established in September 2022. The proceeds from the issue will be used in accordance with the green project categories of Finnfund’s Sustainability Bond Framework to finance and/or refinance eligible green lending, equity investments, and mezzanine financing mainly targeting, for example, the objective of climate change mitigation and adaptation and/or environmentally sustainable management of living natural resources. Net proceeds will be allocated to eligible projects with the objective to mobilise debt capital to support Finnfund’s mission to generate lasting impact by investing in businesses that solve global development challenges. In addition, it contributes to Finnfund’s goal to foster sustainable development by providing investment opportunities for private investors. In its strategy, adopted in January 2022, Finnfund sets one of its targets to fund 50% of its investments with private capital by 2030. Mobilising private capital is key to achieving the UN Sustainable Development Goals (SDGs) in developing countries, given that the UN estimates the financing gap at USD 2.5 trillion per year. Jaakko Kangasniemi, Managing Director, CEO at Finnfund said: “Sustainable, innovative businesses and investors play an integral role in solving both global and local challenges, such as climate change mitigation and adaptation, and biodiversity loss. Capital markets are also vital in the transition away from fossil fuels. We are glad to have such a strong support for our impact investing activity and our mission to foster sustainable development and green transition.” Andrey Medvedev, Senior Vice President at Jefferies said: “We are delighted to have assisted Finnfund issuing its longest private placement to date and showcasing its innovative green projects. This deal demonstrates Finnfund’s appeal to a diversified international investor base and cements its position as a leading development financing agency.”
Case published 26.1.2024
We advised Nala Renewables on the Finnish law aspects of the development, acquisition and financing of its battery energy storage system (BESS) project in Vuolijoki, Finland. The project comprises a 125 MW / 250 MWh battery energy storage system. Our advice extended beyond financing to the transaction’s legal due diligence and the acquisition of the project company. We also advised on key project contracts and financing documentation for the project finance facilities provided by Coöperatieve Rabobank U.A. The project is part of Nala Renewables’ growing portfolio of battery storage assets in Finland and the wider Nordic region, supporting the integration of renewable energy and contributing to the flexibility and stability of the Finnish electricity grid.
Case published 3.11.2026
We advised Foundation Clinic in connection with its funding round backed by a group of prominent Finnish technology entrepreneurs and investors, including founders behind Supercell and Wolt. Foundation Clinic is a Finnish healthcare company developing a new approach to private healthcare focused on preventive, data-driven and continuous care. The company aims to combine comprehensive health data with ongoing medical care to identify and address health risks at an early stage.
Case published 29.10.2026
We advised Delta Capacity AG in a project financing of two battery energy storage systems (BESS). The financed projects are among the largest BESS developments in Finland to enter construction with 250 MW / 600 MWh combined capacity. The financing was provided by Société Générale with support from Finnvera. Construction of both projects, located in Lapinlahti and Teuva, has already begun and the commercial operations are targeted to commence in late 2027 with partial tolling agreements already in place for both assets. The project in Lapinlahti is executed in partnership with Covenergo, while the project in Teuva is executed in partnership with Strioga Family Foundation. Delta Capacity is a Swiss developer of utility-scale battery storage systems. The projects strengthen Delta Capacity’s growing Nordic portfolio and support the flexibility of Finland’s electricity system by adding energy storage capacity, enabling production optimization as well as participation in electricity markets and reserve services.
Case published 28.10.2026
We acted as legal adviser to Martela Corporation in its directed share issue, through which Martela raised gross proceeds of approximately EUR 7.2 million to strengthen the company’s financial position and liquidity and to create headroom for continuing the necessary development and efficiency measures. In connection with the directed share issue, Martela’s unlisted series K shares, which carried greater voting rights, were combined with its listed series A shares. Following the combination, the company has only one share series, which is traded on the regulated market maintained by Nasdaq Helsinki Ltd, with each share carrying one vote and otherwise identical rights. Martela is a Nordic leader specialising in user-centric working and learning environments. With over 80 years of experience, Martela creates the best places to work and offers its customers the Martela Lifecycle solutions which combine furniture and related services into a seamless whole.
Case published 27.10.2026
We acted as legal adviser to Banyan Software on its acquisition of Carus Ferry, a Finland-based provider of reservation, check-in and port operations software for ferry and passenger shipping operators. The acquisition further strengthens Banyan Software’s presence in the Nordic region while providing Carus with a long-term partner to support its continued growth and development. Carus was founded in 1998 and is headquartered in Mariehamn on the Åland Islands, Finland. The company develops mission-critical software for ferry, cruise and passenger shipping operators, covering the full passenger journey from booking and ticketing to capacity management, check-in and boarding. Carus also provides port automation, onboard sales systems and business information tools. The company serves approximately 30 operators across four continents and is the largest vendor by customer count in ferry reservation and departure control. Banyan Software is an acquirer and long-term operator of mission-critical software businesses serving specialised industries. Founded in 2016, Banyan follows a buy-and-hold-for-life approach and supports the long-term growth and development of its portfolio companies. Banyan operates more than 130 portfolio companies across North and South America, the United Kingdom, Europe and APAC. Following the acquisition of Carus, Banyan operates three businesses in the Nordic region.
Case published 20.10.2026