Noora Ahonen

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

Services

  1. Tax & Structuring
  2. Environment, Energy & Green Transition

Contact details

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

Downing – Acquisition of the entire share capital of Tornionlaakson Voima
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
Merger of Oomi and Lumme Energia
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
Finnfund – A EUR 100 million green bond
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
Nscale – Data centre project
Castrén & Snellman advised Nscale, a European AI infrastructure company, in connection with its planned data centre project in Harjavalta, Finland. The facility will be located in the Sievari industrial area. Castrén & Snellman’s advisory role encompassed the negotiation and execution of a site securing and development agreement (SSDA) with Fortum, as well as the preliminary land sale process for the Sievari site with the Town of Harjavalta. Under the SSDA, Fortum supports the advancement of Nscale’s project development, including grid connection design and permitting.
Case published 15.4.2026
Taaleri – Acquisition of a majority stake in Nordic Science Investments
We are acting as legal adviser to Taaleri Plc on its acquisition of a 51 per cent ownership stake in Nordic Science Investments Oy (NSI), marking Taaleri’s expansion into deeptech-driven venture capital. Through the transaction, Taaleri broadens its private equity offering into early-stage venture capital funds as well as the commercialisation and scaling of research-driven innovations. NSI is a Finnish venture capital fund manager operating across the Nordic and Baltic regions, focusing on early-stage investments in research- and science-based technologies. Its portfolio companies develop, among other things, health technologies, life sciences, advanced materials and AI-driven solutions. In addition to providing growth capital, NSI supports spin-out companies with strategic guidance, access to networks and assistance in building teams during the early phases of business development. NSI’s first fund, the EUR 45 million NSI Nordic Science I Ky, was established in 2024 and has to date invested in 22 early-stage companies in Finland, Sweden and the Baltic countries. Taaleri is a specialist in investments, private asset management and non-life insurance, with a strong position in renewable energy, bioindustry and housing investments as well as credit risk insurance. Taaleri has EUR 2.7 billion of assets under management in its private equity funds, co-investments and single-asset vehicles, employs approximately 130 people and is listed on Nasdaq Helsinki. The founders of NSI will continue in their operational roles following the transaction. The completion of the transaction is subject to approval by the FIN-FSA.
Case published 13.4.2026
Finnish Centre for Pensions – Information design workshop
We delivered two information design workshops for the legal department of the Finnish Centre for Pensions, with participants from both legal and other professional backgrounds. In the sessions, we applied the principles of legal design thinking to the Finnish Centre for Pensions’ field of operation and background materials, also utilising AI as a design tool. The participants found the tailored training highly useful and commended the trainers for their in-depth familiarisation with the Centre’s opinion drafting process and operating environment. As a result of the workshops, our experts proposed a new structural and linguistic model for the legal department of the Finnish Centre for Pensions for drafting opinions and guidelines. The proposal was well received as clear and applicable to the participants’ everyday work. In addition, we presented tailored AI use cases to support experts, allowing for a more efficient AI-assisted way of working. Our experts who delivered the workshops combined their legal expertise with their leading experience in legal design. The participants appreciated this versatile expertise, which enabled a knowledgeable, creative and applied approach to legal writing. ‘C&S created a well-structured training tailored to our needs, providing clear direction for our organisation and concrete takeaways for our experts in their day-to-day work,’ says Mari Kuunvalo, Head Of the Legal Department at the Finnish Centre for Pensions.
Case published 10.4.2026
Aktia Bank – EUR 80 million AT1 bond
We advised Aktia Bank Plc on the issuance of an EUR 80 million Additional Tier 1 (AT1) bond. The bond pays a fixed interest rate of 6.75 per cent semi-annually. The bond is perpetual, and Aktia has the right to redeem or repurchase it in accordance with the terms of the bond, subject to certain conditions. The bond was issued on 1 April 2026. In addition, we assisted Aktia in listing the bond on the Nasdaq Helsinki Ltd stock exchange. For the listing, we prepared Finland’s first EU Follow-on prospectus for a bond. The EU Follow-on prospectus was introduced on 5 March 2026 with an update to the Prospectus Regulation (EU) No. 2017/1129. The EU Follow-on prospectus is a new type of prospectus that can be used, among others, by issuers whose securities have been admitted to trading on a regulated market continuously for at least the 18 months preceding the offer to the public or the admission to trading on a regulated market of the new securities. A follow-on prospectus is simpler than a so-called traditional prospectus, and it is intended to avoid repeating information that the issuer has already disclosed. Nordea Bank Abp acts as the sole structuring advisor for the issue of the Notes. Nordea Bank Abp, Danske Bank A/S and ABN Amro Bank N.V. act as the lead managers for the issue of the Notes. 
Case published 7.4.2026
Aurevia and Labquality – Strategic reorganisation
We advised Aurevia Oy, a portfolio company of French private equity sponsor Mérieux Equity Partners, in a strategic reorganisation that involved splitting Aurevia and its parent companies into two independent groups of companies and reorganisation of its existing debt-financing arrangements. Following the reorganisation, the newly formed Aurevia continues as a leading provider of Contract Research Organization (CRO) and Quality Assurance and Regulatory Affairs (QARA) services, while the newly formed Labquality focuses on delivering External Quality Assessment (EQA) services. Aurevia serves operators in the medical devices, in vitro diagnostics and pharmaceutical sectors. Labquality’s customers include clinical laboratories and social and healthcare organisations. The reorganisation positions Aurevia and Labquality to allocate investments more effectively, accelerate growth within their respective customer segments, and respond to evolving market and client needs. The transaction was implemented through multiple parallel demergers and required comprehensive legal and tax structuring across several jurisdictions. Our team supported Aurevia throughout the planning and implementation phases, covering corporate, tax, employment law, and regulatory matters, as well as the optimisation of each group’s financing structure.
Case published 7.4.2026

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