Sebastian Palomäki

Senior Associate, LL.M.

Services

  1. Capital Markets & Public M&A
  2. Private Equity
  3. Financial Regulation

Contact details

I advise our domestic and international clients in various assignments related to capital markets transactions and financial regulation. I also advise our clients in private equity and venture capital investments as well as private M&A.

I have over a decade of international experience studying at international schools in Helsinki as well as studying for my university degrees abroad. I completed my Master of Laws degree at the University of Oslo. During my studies I specialised in various financial regulatory matters with a strong emphasis in emerging technologies.

I joined Castrén & Snellman in 2019 as a trainee. I worked in several trainee positions, which helped me to develop experience in multiple areas of business and financial law.

I’m committed to helping clients and providing sound legal advice in all matters relating to business and financial law. I strive to build trust and long-term relationships by providing sincere communication on legal matters. Through my experience outside of the legal profession, I’m also able to provide outside-the-box solutions to help our clients achieve their goals.

Latest references

Enersize – Rights issue and warrants 
We acted as the legal counsel to Enersize Plc, in its rights issue, where the company raised gross proceeds of approximately MSEK 8.3 in order to promote continued growth and be able to meet increased demand from its customers. The proceeds were allocated to market expansion and sales efforts as well as product, licence and technical validation and development, amongst other things. In connection with the rights issue, warrants were issued free of charge and the subscription period for new shares pursuant to the warrants will run from 1 October 2025 up to and including 15 October 2025. Enersize is a Finnish public limited company having its shares listed on Nasdaq Stockholm First North Growth Market. The company’s shares are traded only in Sweden. Enersize develops and provides software, tools, and services to improve the energy efficiency of industrial compressed air systems, serving industrial companies for whom energy efficiency is both an economic and environmental consideration. With the aim of reducing energy consumption, detecting leaks, and improving performance, its technology enables detailed monitoring, analysis, and real-time optimisation of compressed air systems. 
Case published 21.11.2025
WithSecure – Diana BidCo’s public tender offer on WithSecure
We are acting as the legal advisor to WithSecure Corporation in Diana BidCo Oy’s voluntary public cash tender offer for all the issued and outstanding shares in WithSecure. The tender offer values WithSecure’s total equity at approximately EUR 299 million. Diana BidCo is a private limited company incorporated and existing under the laws of Finland that will be indirectly owned by a consortium formed for purposes of the tender offer by certain affiliated funds of CVC Capital Partners Plc and Risto Siilasmaa. The consortium believes that the partnership strengthens and accelerates the road to WithSecure’s long-standing goal of becoming Europe’s most trusted cybersecurity partner by positioning the company to lead the next era of business cybersecurity. WithSecure’s shares are listed on the official list of Nasdaq Helsinki. WithSecure is a Europe-based cybersecurity company that helps protect businesses and is committed to strong partnerships with customers and collaborators. WithSecure’s customers trust WithSecure with outcome-based cybersecurity that protects and enables their operations. The completion of the tender offer is subject to the satisfaction or waiver by the offeror of certain customary conditions on or prior to the offeror’s announcement of the final results of the tender offer. The tender offer is currently expected to be completed during the fourth quarter of 2025. The Takeover Board of the Securities Markets Association issued on 4 August 2025 a new recommendation (1/2025) on good securities market practice that deals with the target company’s board of directors’ obligations in case of a consortium offer in which a major shareholder of the company participates in the consortium.
Case published 8.8.2025
The Mortgage Society of Finland – Update of EUR 2,5 billion bond programme
We advised The Mortgage Society of Finland in the update of a EUR 2,5 billion bond programme under which the Mortgage Society of Finland may issue senior preferred and unsecured Tier 2 notes, and covered bonds. The notes under the programme may be listed on the official list of Nasdaq Helsinki Ltd.  The Mortgage Society of Finland is the only nationwide credit institution in Finland that focuses on housing. It provides customers with the full range of home financing services such as granting mortgage and consumer loans for all stages of home owning including purchasing and renovating. The Mortgage Society of Finland carries out this activity in accordance with the Act on Credit Institutions and the Act on Mortgage Societies.
Case published 5.8.2025
Piippo – Sale of bale netwrap and baler twine machines and certain trademarks
We are acting as legal advisor to Piippo Plc in the sale of their bale netwrap and baler twine machines, related assets, and trademarks used in Piippo’s business to Portuguese Cotesi S.A. The sale of assets will be carried out in two phases and the final completion of the transaction is expected to occur during the first quarter of 2026. Piippo Oyj’s core business is baling nets and twine and it is one of the leading suppliers in the industry globally. The company’s global distribution network covers more than 40 countries. The company’s shares are listed on the First North Growth Market Finland operated by Nasdaq Helsinki Oy. Founded in 1967, Cotesi is one of the world’s leading producers of synthetic and natural twines, nets and ropes, with operations in Europe, North America and South America and its main production plant in Vila Nova de Gaia, Portugal.
Case published 17.4.2025
Korkia Oy – Renewable energy loan agreement
We advised Korkia Oy in its loan agreement with Nordic Environment Finance Corporation. The financing will support the development and international scale-up of Korkia’s pipeline of solar energy, battery energy storage system (BESS) and onshore wind projects. Korkia is a dedicated investor in renewable energy operating in nine countries. It has a robust development pipeline of over 20 GW in renewable energy and energy storage projects.
Case published 7.1.2025
Enersize – Rights issue
We acted as the legal counsel to Enersize Plc, in its rights issue, where the company raised gross proceeds of approximately MSEK 12.8 in order to promote continued growth and be able to meet increased demand from its customers. The proceeds were allocated to sales and marketing as well as the strengthening of the delivery organisation, amongst other things. Enersize is a Finnish public limited company having its shares listed on Nasdaq Stockholm First North Growth Market. The company’s shares are traded only in Sweden. Enersize develops and provides software, tools, and services to improve the energy efficiency of industrial compressed air systems, serving industrial companies for whom energy efficiency is both an economic and environmental consideration. With the aim of reducing energy consumption, detecting leaks, and improving performance, its technology enables detailed monitoring, analysis, and real-time optimisation of compressed air systems. 
Case published 10.6.2024
SATO – Rights Issue
We advised SATO Corporation and lead manager Skandinaviska Enskilda Banken AB (publ) Helsinki Branch in a rights issue. SATO received gross proceeds of approximately EUR 200 million from the issue. SATO Corporation is an expert in sustainable rental housing and one of Finland’s largest rental housing providers. SATO owns around 25,000 rental homes in the Helsinki Metropolitan Area, Tampere and Turku. Approximately 45,000 residents live in SATOhomes.
Case published 29.2.2024
Purmo Group – Issue of EUR 60 million green hybrid bond
We advised Purmo Group Plc in the issue of a EUR 60 million green hybrid bond. The rationale for the issue is to ensure funding for Purmo Group’s strategy acceleration programme. In connection with the issue, Purmo Group published a green finance framework to integrate the company’s sustainability ambitions into its funding. The net proceeds from the issue will be used in accordance with Purmo Group’s green finance framework. Purmo Group is a leader in sustainable indoor climate comfort solutions in Europe. Purmo Group provides complete heating and cooling solutions to residential and non-residential buildings, including radiators, underfloor heating, heat pumps, towel warmers, valves and controls.
Case published 17.2.2023
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