Security & Defence 

Security & Defence 

The security landscape in Europe has fundamentally changed in recent years. Shifting geopolitical realities and accelerated technological development are creating both new opportunities and new challenges for security and defence operators.

Companies in this field must navigate a highly regulated and rapidly evolving environment. They face increasingly complex compliance requirements, heightened scrutiny around investments and ownership, and growing expectations around ethics and responsible business conduct.

Legal advisor to the security and defence sectors

Castrén & Snellman provides top-tier legal services to domestic and international clients operating in the security and defence industries. Our deep industry knowledge helps clients anticipate legal risks and seize strategic opportunities in a changing world.

We advise both private and public sector organisations across the full corporate lifecycle, from early-stage funding and cross-border structuring to strategic partnerships and regulatory risk management.

Our clients include defence sector authorities, defence tech developers, dual-use manufacturers, critical infrastructure operators, public authorities, institutional investors, banks and venture capital and private equity funds. Many are driving innovation in areas such as space, cybersecurity, AI, connectivity and sustainable technologies.

As the go-to supplier of legal services, we advise security and defence operators, as well as their business partners, on matters such as:

Castrén & Snellman is a trusted legal partner in matters where national security, regulation and geopolitical complexity intersect. Our legal advice helps safeguard operational continuity, promote responsible growth, and support the strategic resilience of the security and defence ecosystem.

Latest references

We advised General Catalyst as lead investor on ICEYE’s EUR 150 million series E funding round, valuing the company at EUR 2.4 billion. ICEYE is the world leader in synthetic aperture radar (SAR) satellite systems and operates the largest SAR constellation globally. Its technology delivers objective, near real-time Earth observation in any weather or light conditions, enabling governments and institutions to manage risks and respond faster. General Catalyst is a global investment and transformation company, partnering with leading entrepreneurs to build toward global resiliency and applied AI. Its portfolio includes companies such as Airbnb, Snap, Stripe, Mistral AI, Hubspot, Anduril, Helsing and Legora. We advised General Catalyst on this transaction in collaboration with the US law firm Goodwin. 
Case published 8.12.2025
We advised Springvest Oyj in organising a EUR 45 million Series A funding round for ReOrbit, a space technology company and a leading provider of software-first satellites. It’s the largest all-equity Series A round in Finland and one of the most significant deals overall in the European space and defence sector. The purpose of the funding round is to support ReOrbit’s growth. The round consisted of a private placement reserved for professional and institutional investors, which included, e.g. Icebreaker.vc, Expansion VC, 10xFounders, Inventure VC, Varma Mutual Pension Insurance Company, and Elo Mutual Pension Insurance Company, and an EUR 8 million public share offering, which was oversubscribed within 4.5 hours. Springvest is a Finland-based investment firm that connects unlisted growth companies with investors. ReOrbit builds sovereign satellites and connected systems for national security.
Case published 9.9.2025
Castrén & Snellman advised the lead investors Ten Eleven Ventures and Tesi in the EUR 275 million Series B financing round of IQM Quantum Computers, the global leader in building quantum computers. The round is largest Series B round ever in Finland and the second largest in the Nordics. In addition to the lead investors represented by C&S, the round was participated by several new and existing investors, including pension funds Elo Mutual Pension Insurance and Varma Mutual Pension Insurance, strategic investors Companies of Schwarz Group and Winbond Electronics Corporation, and sovereign wealth funds EIC and Bayern Kapital. Ten Eleven Ventures is the original cybersecurity-focused, global, and stage-agnostic investment firm. The firm identifies, invests in, and helps grow top cybersecurity companies addressing critical digital security needs, leveraging its team, network, and experience to build successful businesses. Since its founding, Ten Eleven Ventures has raised over USD 1 billion and made over 60 cybersecurity investments across various stages worldwide. Tesi (Suomen Teollisuussijoitus Oy / Finnish Industry Investment Ltd) is a state-owned investment company with an industrial policy mission focused on driving economic growth, renewal, and investments. Tesi invests on market terms both in venture capital and private equity funds, and directly in startups, scale-ups, and large industrial projects. IQM Quantum Computers, founded as a deep tech spin-off from Aalto University in 2019, specialises in developing quantum computers utilizing superconducting circuits. The company designs and produces quantum processors at its facility in Espoo, providing computing solutions and optimizations tailored to both research and industrial applications. In addition to its Finnish operations, IQM has expanded its presence to Germany, France, Italy, Japan, Poland, Spain, Singapore, South Korea, and the United States.
Case published 4.9.2025
We acted as Finnish legal advisor to HANZA AB in connection with its acquisition of the contract manufacturing division of Milectria, a group of companies specialising in electrical systems for the defence industry.  The transaction comprises 100% of the shares in Milectria Oy (Finland), Milectria OÜ (Estonia), and the real estate company Kiinteistö Oy Kanungin Karhu. The transaction is expected to close in September 2025, subject to customary closing conditions, including regulatory approvals.  Founded in 2008, HANZA is a Swedish mechanical engineering and electronics contract manufacturing company listed on the Nasdaq Stockholm main list. The company operating in seven countries currently has annual sales of approximately SEK 6 billion and approximately 3,100 employees. Milectria is a Finnish contract manufacturer of electrical systems for the defence industry.
Case published 21.7.2025