WALTER CARLSON has regularly served as lead counsel in securities litigation, shareholder derivative suits, M&A litigation, and defense of SEC enforcement matters. He has first-chaired major matters in state and federal courts across the country for more than 25 years. He was co-head of the firmwide Securities and Shareholder Litigation practice area team for many years and served as a member of the firm’s Executive Committee from 2002–2018.
Walter’s experience and success has been recognized in Chambers USA in Litigation since 2003, in The Legal 500 US for many years, in Benchmark Litigation as a “Litigation Star” (2008–2025), and in Best Lawyers since 2006. Walter has been recognized as “Securities Lawyer of the Year for Illinois” by Best Lawyers and is recognized for Bet-the-Company Litigation, Litigation — Mergers & Acquisitions, Litigation — Securities, and Commercial Litigation.
Walter has regularly represented clients in major securities, shareholder derivative and M&A litigation matters. Among his recent successes are the following representative engagements:
- Representation of Zebra Technologies and its current and former executive officers in defense of federal securities litigation in the Northern District of Illinois. Case transferred to the Northern District from the Eastern District of New York. Motion to dismiss granted and the dismissal was affirmed on appeal by the Seventh Circuit.
- Representation of NiSource Inc. and its current and former directors in defense of federal proxy claim litigation in the District of Delaware. Motion to dismiss granted. Subsequent shareholder derivative suit filed in Delaware Court of Chancery. Motion to dismiss granted.
- Representation of Las Vegas Sands Corporation and its CEO and Chairman in defense of federal securities litigation in the District of Nevada. Proposed claims substantially narrowed by motions to dismiss. Following fact and expert discovery, summary judgment granted for defendants. The District Court’s grant of summary judgment was affirmed by the Ninth Circuit.
- Representation of Caterpillar Inc. in various securities and derivative suits filed in the District of Delaware, the Central District of Illinois, and the Eastern District of Wisconsin involving a variety of matters, including alleged proxy claims, litigation challenging Caterpillar’s acquisition of Bucyrus International, and shareholder derivative litigation relating to Caterpillar’s acquisition of ERA Mining. All complaints dismissed.
- Representation of Discover Financial Services in defense of shareholder derivative suits filed in the Northern District of Illinois and in Illinois state court arising from Discover Bank’s settlement with the FDIC and CFPB. All complaints dismissed.
Walter is the non-executive Chairman of the Board of Directors of Telephone & Data Systems, Inc. and a member of the Board of Directors of United States Cellular Corporation. He has previously served as Chairman of the Audit Committee for each of these companies.
Walter joined Sidley in 1980 and became a partner in 1986. He clerked for the Honorable Hubert L. Will of the United States District Court for the Northern District of Illinois from 1978–1980.