Greta L. Nightingale is chair of O’Melveny’s National Security Group. Greta’s practice focuses on compliance with US laws that govern international business transactions and trade. She represents and advises clients in matters related to US economic sanctions, export controls, anti-corruption (the Foreign Corrupt Practices Act, or “FCPA”), foreign investment, money laundering, antiboycott, and customs laws. In addition to advising clients on the application of these laws to on-going business and potential acquisitions, Greta assists clients in all aspects of managing compliance with these laws, including developing corporate compliance programs, conducting internal investigations relating to potential violations of these laws, and representing companies before the relevant agencies in connection with enforcement proceedings, clearances, license requests, and government inquiries. These include the Treasury Department’s Office of Foreign Assets Control (OFAC), the Committee on Foreign Investment in the United States (CFIUS), the Departments of Justice, Commerce and State, the Securities and Exchanges Commission (SEC), and the US Bureau of Customs and Border Protection.
Greta is highly ranked by both Chambers USA and Chambers Global. Chambers has described her as the “dean of the sanctions bar” and notes that in the area of export controls she “combines experience with technical knowledge to provide extremely valuable counsel,” is “very knowledgeable about the arcana in this area” and “very skilled at helping the client get that end result.” Chambers also notes Greta’s “great contacts at OFAC” and “very commercial approach” as key strengths. Greta has deep experience advising clients in a range of industry sectors, including financial, insurance, Fintech, energy, semiconductor, defense, and telecommunications.
Enforcement Proceedings and Internal Investigations
- Conducts internal investigations relating to potential violations of economic sanction laws, antiboycott laws, the FCPA, the Export Administration Regulations (EAR), and the International Traffic in Arms Regulations (ITAR) and Customs rules.
Compliance Risk Assessments and Audits
- Conducts assessments and audits of compliance programs in a variety of industries.
Due Diligence and Post-Investment Planning
- Advises parties on FCPA and trade controls due diligence within the context of mergers and acquisitions, financings, and IPOs. Assists with due diligence, appropriate contractual protections and undertakings, as well as post-acquisition planning.
Development of Compliance Programs and Procedures
- Advises companies in a wide range of sectors on the development and implementation of corporate compliance programs in the areas of FCPA, export controls, economic sanctions, customs, and the antiboycott laws.
Licensing, Classifications, and Advisory Opinions
- Represents US and foreign companies in obtaining a range of authorizations, licenses and advisory opinions under the EAR, the ITAR, as well as the economic sanctions regulations governing trade with Cuba, Iran, Iraq, Libya, Sudan, and Syria.
Counseling
- Advises companies in various sectors (including semiconductor, oilfield services, energy exploration, hospitality, insurance and reinsurance, and a range of other financial services) on legal issues arising under trade controls, anti-bribery, antiboycott, customs, and anti-money laundering laws.
Government Proceedings and Inquiries
- Prepared a number of voluntary notices and mandatory declarations to CFIUS on behalf of both non-US investors and domestic firms.
Admissions
Bar Admissions
- District of Columbia
Education
- Harvard University, J.D., 1990: Managing Editor, Harvard Human Rights Journal; Member, International Law Society
- Haverford College, B.A., 1986: Phi Beta Kappa, Departmental Honors
Honors & Awards
- Recognized by Best Lawyers® for International Trade and Finance Law in Washington, DC (2025)
- Ranked Band 1 by Chambers Global and Chambers USA in the category of International Trade: Export Controls & Economic Sanctions (2009-2014, 2024-2025; 2016-2024)
- Ranked by Chambers USA in the category of International Trade: CFIUS Experts (2022-2024)
- Recognized by Chambers Global for International Trade: CFIUS Experts (2022, 2024-2025)
- Recognized as a "Leading Lawyer" by The Legal 500 US for International Trade: CFIUS (2014-2024)
- Named one of Global Investigation Review’s “25 Most Respected Sanctions Lawyers” in Washington, DC (2019)
- Recommended in Trade & Customs (2018-2019); Trade & Customs - International Sanctions (2019) by Who’s Who Legal
- Named a “Super Lawyer” in International Law in Super Lawyers - Washington, DC edition (2013-2014; 2017)
- Recognized by BTI as a “Client Service All-Star” (2013)
- Recognized in The Guide to the World’s Leading Women in Business Law (2012)
- Named a “Super Lawyer” in Super Lawyers - Corporate Counsel Edition (2010-2012)
- Recognized in The Guide to the World’s Leading International Trade Lawyers (2010 and 2012)
Professional Activities
Publications
- “Managing Humanitarian Activities During Sanctions,” Export Compliance Manager, Issue 41 (March 2024)
Speaker
- "A Deep Dive Into Russia Sanctions: A Comprehensive Look at the Key Differences between US, UK and EU Restrictions," 17th Annual Flagship Conference on US Economic Sanctions Enforcement and Compliance (April 2023)
Client Alerts (Most Recent)
- “CFIUS Plans to Enhance and Expand Monitoring and Enforcement Authorities” (O’Melveny National Security Alert, April 2024) (with David J. Ribner)