Sidley Austin LLP maintains a leading shareholder activism practice advising boards and senior management, with a strong track record in takeover approaches, proxy contests, settlement negotiations, and related litigation across a range of industries. The team regularly advises on activism preparedness, shareholder engagement strategy, and defense against activist demands, including matters involving board reconstitution, cooperation agreements, and negotiated resolutions. The group is led by New York-based Kai Liekefett, who is particularly experienced in late-stage proxy contests and campaign defense strategy, and Palo Alto-based Derek Zaba, noted for his corporate governance and takeover defense work. Jessica Wood focuses on hostile takeover defense and public company M&A transactions, while Eric Goodwin advises on conflicted transactions and special committee mandates arising from activist pressure. Demetrius A. Warrick joined from Skadden, Arps, Slate, Meagher & Flom LLP in April 2025, and Leonard Wood left the firm in August 2025.
Legal 500 Editorial commentary
Testimonials
Collated independently by Legal 500 research team.
- ‘They are the leading global practice in this space.’
- ‘Top-tier client service and deep subject matter knowledge.’
- ‘The largest and most experienced shareholder activism practice in the country. The team combines strong legal execution with strategic insight and is supported by a deep bench that consistently impresses.’
- ‘Kai Liekefett is one of the most formidable and capable activism defense lawyers in the country, with deep knowledge of the law, tactics, and campaign strategy. He is a strong and loyal advocate for his clients.’
- ‘Derek Zaba is thoughtful and sharp, with a measured and strategic approach. As a former activist, he brings a perspective that is rare within the activism defense bar.’
Key clients
- The New York Times Company
- BlackRock, Inc.
- Beacon Roofing Supply, Inc.
- Cannae Holdings, Inc.
- Matthews International Corp.
- Alight, Inc.
- Riot Platforms, Inc.
- Rogers Corp.
- WEX Inc.
- Portillo's
- Bausch Health Companies Inc.
- National Vision Holdings, Inc.
Work highlights
Representing The New York Times Company in its defense against an activist campaign launched by Fivespan Partners, a new fund formed by former ValueAct partners.
Successfully defended BlackRock, the world’s largest asset manager, in its back-to-back proxy contests in 2024 and 2025 against Saba Capital in one of the most high-profile activism matters in recent years.
Represented Beacon Roofing Supply, the largest publicly traded distributor of roofing materials in the U.S., in its defense against a bold unsolicited takeover bid from Brad Jacobs’ QXO Inc.
Lawyers
Leading lawyers: Advice to boards
The strongest partners in their field, leading on market-leading deals and endorsed by peers and clients alike.
Derek Zaba
Practice head
Kai Liekefett; Derek Zaba
Other key lawyers
Eric Goodwin; Demetrius A. Warrick; Jessica Wood