Mark P. Guerrera

Partner, Sidley

Washington D.C.


Mark Guerrera, co-leader of the Commercial Litigation and Disputes group, represents corporations in commercial litigation, dispute resolution, and in government investigations. He has tried cases in federal court and before regulatory agencies, and has defended clients in cross-border litigation in Italy, Liechtenstein, Switzerland, and the Cayman Islands, among others. Mark has represented clients in the financial services, government contracting, real estate, pharmaceutical, energy, and telecommunications industries in litigation involving allegations of fraud and other business torts, breach of fiduciary duty, deepening insolvency, market manipulation, unfair business practices, securities fraud, breach of contract and violations of state and federal statutes, including the False Claims Act and RICO. He also has litigated class action securities matters, government contracts disputes, bid protests and intellectual property disputes. A number of the cases Mark has litigated have involved multi-billion dollar damage claims.

Mark also has conducted internal investigations on behalf of companies in the U.S. and abroad has defended companies in connection with government investigations regarding allegations of fraud, accounting irregularities, employee misconduct and violations of the False Claims Act, anti-bribery, anti-money laundering, federal securities and banking laws.