Cleary Gottlieb Steen & Hamilton is sought out by a client base spanning sovereign wealth funds, asset managers, and multinational companies, for assistance handling deals involving CFIUS assessments, and negotiating mitigation agreements. The team has demonstrated capabilities in the energy, semiconductors, and aerospace and defense sectors. Foreign investment and national security team head Chase Kaniecki has a proven track record filing CFIUS notices and negotiating mitigation agreements. B.J. Altvater has played an integral role in negotiating complex and significant national security agreements, with experience litigating a CFIUS outcome. Samuel Chang, who was promoted to partner in 2025, is another key attorney.
Legal 500 Editorial commentary
Testimonials
Collated independently by Legal 500 research team.
- ‘What sets Cleary Gottlieb’s CFIUS practice apart is the team’s ability to translate complex national security review risks into actionable, commercially sound advice that aligns with an investor’s strategic objectives.’
- ‘Chase Kaniecki and B.J. Altvater combine deep procedural knowledge of the CFIUS process with an acute understanding of how U.S. regulators assess foreign investment in sensitive sectors. Their work is practical, not academic, and consistently calibrated to real-world investor concerns, including timing, risk mitigation, and deal execution.'
- 'What we value about this team is their early issue identification, clear communication, and strategic positioning of filings in a way that anticipates regulator expectations without compromising investment outcomes. They do not merely prepare notifications; they help shape the framing of transactions in a manner that reduces uncertainty and supports broader governance obligations.'
- 'The practice operates with an integrated mindset, collaborating across disciplines and time zones so that CFIUS considerations are embedded into the broader structuring and negotiation process rather than layered on retrospectively. This approach reflects a client-first ethos that, from our perspective, distinguishes them from peers.’
- ‘What distinguishes Chase Kaniecki and B.J. Altvater is their ability to combine deep technical expertise with an exceptionally clear and pragmatic communication style. They consistently break down issues in a way that is accessible to all stakeholders in the room, regardless of experience or sophistication, without oversimplifying or losing legal precision.'
- ‘Chase Kaniecki and B.J. Altvater anticipate issues before they arise, flag risks early, and provide structured options rather than abstract analysis. This is particularly valuable in transactions involving sovereign investors, where decisions often involve investment teams, senior management, risk, and legal stakeholders with different perspectives and priorities.'
Key clients
- Dow
- Henkel
- Synopsys, Inc.
- Latour Capital
- ABB
- GVS S.p.A
- ENI S.p.A.
- Amundi S.A.
- IMM Investment Corp
- Kencoa Aerospace
- Dooson Robotics
Work highlights
Advised Synopsys, Inc., a chip design and software firm, on global FDI and DCSA clearances in connection with its $35 billion acquisition of Ansys, an engineering and product design software firm.
Advised Latour Capital in securing CFIUS approval for its acquisition of a majority interest in Systra, an engineering company specializing in rail and urban transport.
Advised ABB in obtaining CFIUS approval for the formation of a joint venture with the Niedax Group to deliver advanced cable tray solutions and services to electrical contractors, distributors, and systems integrators across the United States.
Lawyers
Leading partners
The strongest partners in their field, leading on market-leading deals and endorsed by peers and clients alike.
Leading associates
Leading associates with regular involvement in their team's key work, and recognition from peers or clients as being ones to watch.
B.J. Altvatar
Practice head
Chase Kaniecki
Other key lawyers
B.J. Altvater, Samuel Chang