Sanna Husu

Legal Assistant

Services

  1. Employment

Contact details

I assist lawyers in our Employment Law service.

As an assistant, I am driven by ambition and the desire to assist our lawyers in their everyday work. I am good at organising my work efficiently with a positive attitude even under pressure. Working in a challenging environment and having the possibility to learn every day motivate me.

I started my career at Castrén & Snellman as a Trainee Assistant in the autumn of 2017. I am a BBA graduate of Haaga-Helia University of Applied Sciences. Previously I have worked as a Cultural Manager graduate in a variety of event productions.

Latest references

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
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
CapMan Infra’s portfolio company Koiviston Auto Group – EUR 300 million refinancing
We advised CapMan Infra’s portfolio company Koiviston Auto Group, Finland’s largest bus operator, in a finance arrangement in which it completed an approximately EUR 300 million refinancing. The transaction consists of the refinancing of the Group’s existing senior debt and secures long-term growth financing to support the Group’s continued investments in its rapidly expanding electric bus fleet. The financing package has been provided by a group of lenders consisting of Nord/LB, ABN AMRO, Edmond de Rothschild, LBP AM and Siemens. The transaction strengthens Koiviston Auto’s funding base and provides significant flexibility to execute the company’s growth strategy focused on sustainable public transportation. CapMan Nordic Infrastructure I acquired Koiviston Auto in December 2021 to support its expansion and operational development. The Group now serves communities nationwide and is at the forefront of the transition to zero-emission public transport in Finland. It operates approximately 300 electric buses, with more than 50 additional electric buses expected to be deployed into traffic during 2026, further accelerating the electrification of its fleet. “The successful completion of this refinancing marks an important milestone for Koiviston Auto Group,” says Henrik Mikkola, CEO of Koiviston Auto Group. “The strong support from a diversified group of high-quality lenders underlines the robustness of our business and our long-term strategy. This financing allows us to continue investing in electric mobility and to provide reliable, sustainable and high-quality public transport services across Finland.” “Koiviston Auto Group plays a key role in the green transition of public transportation in Finland,” comments Ville Poukka, Managing Partner at CapMan Infra. “This refinancing significantly strengthens the company’s financial platform and enables continued investments into electric buses at scale. We are pleased to see strong lender confidence in the company’s strategy, operational performance and long-term growth prospects.”
Case published 25.3.2026
Fingrid – Update of EMTN Programme
We advised Fingrid Oyj on the Finnish law aspects in the update of a EUR 3 billion Euro Medium Term Note programme (EMTN). Notes issued under the programme may be listed on the Irish Stock Exchange. Fingrid operates Finland’s main electricity transmission grid and all significant cross-border transmission connections. The main grid is the backbone of the electricity transmission network, to which major power plants, industrial plants and regional electricity distribution networks are connected.
Case published 17.3.2026

Get to know our other experts in the field

Tomi Kemppainen
Position: Partner
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 +358 40 354 2204
Outi Tähtinen
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 +358 50 324 7377
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 +358 20 776 5113
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Suvi Kettunen
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Jutta Nieminen
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Position: Senior Associate
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Ville Kukkonen
Position: Senior Associate
Primary service Employment
 +358 20 776 5497
Sofia Seppänen
Position: Senior Associate
Primary service Employment
 +358 50 550 1274
Mari Kulmakorpi
Position: Associate
Primary service Employment
 +358 20 776 5016
Werner Laitinen
Position: Associate
Primary service Employment
 +358 20 776 5132
Anniina Perkiö
Position: Associate
Primary service Employment
 +358 40 707 2405
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Position: Associate
Primary service Employment
 +358 40 758 7078