“As a former Chief of Staff to the US Trade Representative . . . Tim Keeler has a deep understanding of how the Administration and Capitol Hill work together to advance and develop US trade policy.”

"He understands the law and has really good instincts with how things will be handled by CFIUS."

Legal 500 US and Chambers USA


Tim is a partner and Co-Lead of Mayer Brown’s International Trade Product Team, as well as heading the firm’s Committee on Foreign Investment in the US (CFIUS) practice. He is also a member of the firm’s Public Policy, Regulatory & Government Affairs group. Tim joined Mayer Brown in 2009 after a varied career in the US Government, serving at the Office of the US Trade Representative (USTR), the US Treasury Department (which chairs CFIUS), and the US Senate Finance Committee.

Following eight years of service in the US executive branch on CFIUS member agencies, Tim handles all aspects of CFIUS work, including:

  • Assessing whether prospective transactions raise national security issues
  • Advising whether a transaction is subject to mandatory filing pursuant to CFIUS regulations
  • Advising on how to structure transactions to mitigate national security concerns while achieving business objectives
  • Implementing all phases of regulatory clearance under the CFIUS process, including:
    • Developing messages to be conveyed to CFIUS
    • Preparing Notices and Declarations
    • Presenting on behalf of proposed transactions
    • Negotiating mitigation agreements to satisfy CFIUS concerns
  • Advising on successful engagements involving complex and novel areas of concern for CFIUS
  • Helping anticipate and address government relations and public relations issues that may complicate the successful completion of the regulatory review process

Tim also advises and advocates for clients on high-profile International Trade law and policy, including investigations and tariff actions by the USTR under Sec. 301 of the Trade Act of 1974; safeguard investigations and tariff remedies by the International Trade Commission (ITC) and the USTR under Sec. 201 of the Trade Act of 1974; the consistency of various legal regimes – or proposed laws – with World Trade Organization (WTO) rules and other international legal obligations; international trade negotiations in the WTO, Free Trade Agreements, and other arrangements; and WTO and other trade agreement litigation.

Prior to joining Mayer Brown, Tim served in a variety of senior positions in the US Government for almost 12 years. He was the Chief of Staff in the Office of the US Trade Representative (USTR) from 2006 - 2009, where he oversaw implementation of US policy, strategy and negotiations involving all aspects of international trade and investment matters. He worked on a number of key issues including: climate change and trade; US and China relations; WTO negotiations and litigation; free trade agreement negotiations and implementation; and CFIUS decisions.

Before working for USTR, Tim spent more than five years at the Treasury Department from 2001 – 2006. He joined the Office of Legislative Affairs in 2001 as a Deputy to the Assistant Secretary for International Issues, where he was responsible for Treasury’s legislative strategy on issues including CFIUS, foreign exchange rate policy testimony, appropriations for US funding of the World Bank, and US participation in the International Monetary Fund. He later managed the Office of Legislative Affairs from 2002 - 2006 and assisted on all policy and personnel issues in the Office. This included leading Treasury nominees through the US Senate confirmation process, and legislative strategy on Treasury Intelligence and Anti-Terrorist Financing matters.

Tim also served on the Presidential Transition Team in 2000–2001 as a policy coordinator on export control and trade remedy policy, handling the Commerce Department’s Bureau of Export Administration (now called the Bureau of Industry and Security) and the International Trade Commission (ITC). Earlier in his career (1998-2000), Tim served as a professional staff member for international trade on the US Senate Finance Committee under Chairman William V. Roth (R-DE).

In recognition of his government service, Tim was awarded the USTR Distinguished Service Award, the Treasury Distinguished Service Award, and the Treasury Secretary’s Honor Award twice.

Tim is a member of the Board of Directors of the Washington International Trade Association. He was also an Adjunct Professor at Georgetown University in both the School of Law (2010 – 2017)—co-teaching a course on US and WTO law, policy, and politics, and the School of Foreign Service (2018).


  • Anglais


Tim’s significant engagements include:

  • The $5 billion acquisition of a data historian software and software as a service (SAAS), whose customers included US critical infrastructure companies and US Government (USG) agencies, and which required the successful negotiation of a novel NSA.
  • The $1.2 billion acquisition of a software and SAAS provider for the design, modeling, analysis of electrical networks, whose customers include US critical infrastructure and USG agencies, with the successful negotiation of a next-generation NSA.
  • The acquisition of a SAAS provider of applications designed to manage and optimize renewable and distributed energy resources, which required the renegotiation of an existing NSA.
  • The addition of a new Hong Kong-based investor into an existing NSA, successfully convincing CFIUS that no renegotiation of the NSA, and no separate filing, was necessary.
  • A $250 million investment in a next-generation nuclear reactor company by two South Korean companies.
  • A $475 million investment by an investment fund in a transcontinental company that manufactures solar photovoltaic trackers and develops photovoltaic energy projects.
  • The sale of a majority interest in a port terminal at one of the largest maritime ports in the US to a Japanese joint venture.
  • Providing CFIUS advice on structuring matters to a consortium of non-US lenders in the bankruptcy proceedings of a significant gas-fired power facility.
  • Two Japanese companies’ strategic investment in a global mapping and location services software company.
  • John Hancock’s $415 million investment in a commercial renewable energy portfolio owned by Duke Energy, comprising roughly 1.2 GW of renewable energy assets.
  • A South Korean company’s acquisition of certain semiconductor equipment businesses of Aixtron, Inc.
  • Sinochem Group’s $1.5 billion purchase of interests in Texas’ Wolfcamp Shale properties held for drilling by Pioneer Natural Resources Company.
  • A US energy distributor’s transactions with three separate foreign investors forming two REITs to develop and acquire electricity and gas transmission, storage and distribution assets.


Tulane University, BSE, Engineering Science

George Mason University School of Law, JD, magna cum laude
Associate Editor, George Mason Law Review

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  • District of Columbia


  • Adjunct Professor of Law (2010-2017), Georgetown School of Law
  • Adjunct Professor (2018), Georgetown School of Foreign Service
  • Member, Board of Directors, The Washington International Trade Association
  • Term Member, Council on Foreign Relations (2010-2015)
  • "As a former Chief of Staff to the US Trade Representative and a former legal counsel on the House Ways and Means Committee, Tim Keeler has a deep understanding of how the Administration and Capitol Hill work together to advance and develop US trade policy." - Legal 500 USA
  • "Timothy Keeler has a deep and substantive understanding of the evolving CFIUS and trade policy landscape. He has a deep network of connections that are difficult to match." - Legal 500 USA
  • Ranked by Chambers USA for International Trade: CFIUS Experts – Nationwide
  • "Among the best for customs law," Mayer Brown provides "service of the highest level in all aspects." - Legal 500
  • Who’s Who Legal (WWL) – Recommended: Trade & Customs