Mark C. Williams is a partner in Washington, DC. on the Energy Regulatory and Markets team.
He has experience advising investors and energy companies on corporate, financial, securities and related regulatory matters before the US Federal Energy Regulatory Commission (FERC) and state utility commissions. Mark advises private equity fund managers, generating companies, lenders, sovereign investors and project developers, both on transactions and as portfolio counsel.
- FERC counsel of record to several national fund complexes in their acquisition and management of fleets of over 70 generating companies
- Major insurance holding company owning over 15,000 MW of US electric generation in sale and disposition to global investment management complex
- Private equity funds, advisers, and managers invested in US generation and transmission businesses on the regulation of inter-fund transactions and sales of managers and advisers.
- Major distributed renewable energy developer in its initial public offering.
- Large generating company in FERC enforcement proceedings, leading to favorable findings and a dismissal of the investigation.
- Foreign governmental investor in acquisition of interests in two major US utility systems.
- Private equity fund seller and major generating company in sale to state instrumentality.
- Private equity fund seller and major generating company in sale to investor-owned utility.
- Private equity fund seller and major generating company fleet in sale of controlling interests in facilities in eight states.
- Investors and targets in over 200 FERC-regulated merger, acquisition, securities, and change-in-control proceedings.
- Creditors and distressed energy companies in FERC proceedings authorizing bankruptcy court actions and alternative restructurings.
News and client work
Contact details
- Clifford Chance, Washington D.C.
- (202) 912-5909
- Email me
- Practice area Global Financial Markets
Career & qualifications
- Columbia University (BA), 1987
- New York Law School (JD), 1990
- Admitted Attorney-at-Law in New York 1992
- Admitted Attorney-at-Law in Washington, DC 1999
- Joined Clifford Chance US LLP 2025
Professional bodies
- Member, American Bar Association
- Commissioner, City Industrial Development and Revenue Bond Authority, City of Alexandria, VA (Term 2002–2020; Chairman, 2012–2020)
- Trustee, Foundation of the Energy Law Journal (2011–2014)
- Energy Bar Association: Vice Chair (2008–2010) and Chair (2010–2011) Committee on Professional Development and Ethics; Vice Chair, Chair-elect, and Chair, Committee on Finance and Transactions (2005–2007); Co-chair, Programs and Meetings Committee (2005–2006); Conference Chair, National Legislative Program (2005); Elected Member, Board of Directors (2002–2005); Founding Chair, Committee on Finance and Transactions (1999–2000); Chair, Committee on FERC Administration and Reorganization (1998–1999
- Adviser to US Congress, House of Representatives, Subcommittee on Regulatory Reform and Paperwork Reduction (105th Congress) in connection with national electric-sector oversight hearings (1998)
Awards and citations
- Recognized for inclusion in The Best Lawyers in America (Woodward/White, Inc.), Energy Law, 2026
- Chosen for inclusion in the Chambers USA Legal Directory (Chambers & Partners) of recognized practitioners for Energy: Electricity (Regulatory & Litigation) Nationwide, 2007-2025
- Chosen for inclusion in the Chambers Global (Chambers & Partners) for Energy: Electricity (Regulatory & Litigation), 2012-2025
- Chosen for inclusion in The Best Lawyers in America (Woodward/White, Inc.), Project Finance Law