Fiiu Linninen

Senior Associate, Member of the Finnish Bar, Bachelor of Business Administration

I advise clients on a wide range of legal issues related to the environment, natural resources and infrastructure in matters such as project planning and development, authority negotiations and procedures, administrative proceedings, business transactions and financial arrangements. My core expertise includes matters related to environmental and other permits, EIA processes, land use, environmental liability and nature conservation.

Prior to joining Castrén & Snellman, I worked at another business law firm, advising clients operating in sectors such as mining, forestry and energy. My clients include, for example, companies engaged in exploration and mining, ports and terminal operators, bioproduct plants, wind and solar power plants, and waste treatment and incineration plants.

I graduated from the University of Helsinki in 2020 with a Master of Laws degree. I also hold degree in business administration from a university of applied sciences, which has equipped me with an even better understanding of our clients’ business and needs.

Latest references

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
Castrén & Snellman successfully assisted Terrafame Ltd in environmental and water management permit processes concerning the company’s entire operations and the KL1 side rock area, on which the Supreme Administrative Court issued its decision on 12 February 2026 (KHO 366/2026 and 367/2026). The changes made to the decisions of the Vaasa Administrative Court as a result of Terrafame’s appeals, enable the company to implement its new strategy and develop its operations as planned. The decisions of the Supreme Administrative Court brought the nearly ten-year-long permit process to a close.
Case published 20.2.2026
We advised a leading global investment firm Brookfield, alongside a global sovereign wealth investor, on the Finnish law aspects of a EUR 1 billion holdco financing for DayOne Data Centers, a Singapore-headquartered developer and operator of hyperscale data centres. Structured as a seven-year secured holdco financing facility of €500 million, expandable to €1 billion – and secured by DayOne’s Finland platform – the financing will support the rollout of hyperscale developments in Lahti and Kouvola, providing nearly 300MW of planned capacity across Finland. The proceeds will also support DayOne’s global expansion across the EU and APAC, with flexibility to allocate to other key growth markets as required.
Case published 29.1.2026
We advised G&W Electric with its acquisition of Safegrid Oy, a leading provider of intelligent grid monitoring solutions based in Finland. The acquisition accelerates G&W Electric’s long-term strategy to integrate intelligent monitoring and predictive analytics into its power distribution portfolio, strengthening its offering to utility customers worldwide. Founded in 1905 and headquartered in Bolingbrook, Illinois, G&W Electric is a global leader in innovative power grid solutions, with a presence in over 100 countries. The company is known for advanced load and fault interrupting switches, reclosers, sensors, system protection equipment, power grid automation, intelligent grid monitoring, and transmission and distribution cable accessories. Safegrid is a Finnish technology company headquartered in Espoo, Finland. The company develops the Intelligent Grid System®, a grid monitoring solution that combines instant-on wireless sensors with advanced analytics to deliver real-time insight into grid conditions, enabling utilities to identify emerging issues, anticipate failures, and reduce outage duration across medium and high voltage distribution and transmission networks.
Case published 8.5.2026
We advised Kiwa in its acquisition of Sertio Oy, a Finnish notified body designated by the authority in accordance with the EU Regulation on in vitro diagnostic medical devices (IVDR). Sertio provides conformity assessment services in accordance with IVDR. Kiwa is one of the world’s leading testing, inspection, and certification companies, operating in over 35 countries. 
Case published 7.5.2026
We advised Metsäkonepalvelu Oy in its acquisition of the entire share capital of Junnonen Forest Oy, a Finnish timber harvesting services company, and the timber harvesting services business of Lamerit Oy. The acquisition supports Metsäkonepalvelu’s growth strategy and strengthens the company’s position, particularly in southeastern Finland. Metsäkonepalvelu is a portfolio company of A. Ahlström Oy, a Finnish family-owned industrial owner. The company provides mechanical timber harvesting services to forest companies, large private forest owners, and the public sector in Finland and Sweden. Metsäkonepalvelu Group employs nearly two hundred forestry professionals.
Case published 6.5.2026
We acted as Finnish counsel to Scanreco in its acquisition of CrossControl. Mannheimer Swartling (Sweden) acted as lead counsel for Scanreco. CrossControl, founded in Sweden, is a high-tech supplier of advanced display computers and central vehicle computing solutions for industrial vehicles and machines. Scanreco is a world leading supplier of professional radio remote control systems to international machinery, heavy equipment, and crane manufacturers. The combined group comprises approximately 600 employees and generates annual revenue of around SEK 1.4 billion.
Case published 5.5.2026
We advised the NATO Innovation Fund as lead investor on Kelluu’s EUR 15 million Series A funding round, with participation from Keen Venture Partners, Gungnir Capital, and Tesi. Kelluu is a Finnish deep tech company operating the world’s largest autonomous airship fleet. We advised NIF on this transaction alongside global law firm Latham & Watkins.
Case published 17.4.2026