Executive & Management Team

Luis Hewitt

Director of Communications

Leads global media relations, executive visibility, and crisis communications across TSI's client portfolio.

Alexander P. Vance

Global Strategic Relations & Forum Coordination

Directs global strategic advisory and institutional facilitation, including delegation nominations and forum coordination.

Margaret Ellison

Executive Vice President & Head of Federal Government Affairs

Washington & Federal Practice

Margaret leads TSI's federal practice with two decades of Hill oversight and regulatory experience. She advises corporate leaders on high-stakes legislative strategy and federal agency engagement.

Catherine M. Doyle

Managing Director & Global Head of Sovereign Engagement

Riyadh, Singapore & Cross-Border Corridors

Catherine oversees sovereign engagement and cross-border expansion across the Gulf and Asia-Pacific. She directs foreign direct investment advisory and government-to-government strategic partnerships.

Richard T. Calloway

Senior Managing Director, Legislative & Regulatory Advisory

Regulatory & Legislative Strategy Group

Richard advises board members and C-suite executives on legislative risk and complex agency rule-making. He designs proactive policy strategies to protect commercial interests in heavily regulated markets.

Denise Whitfield

Vice President, Public Affairs & Strategic Coalitions

Campaigns & Grassroots Mobilisation

Denise leads multi-stakeholder advocacy campaigns and high-impact political communications. She pairs targeted grasstops mobilisation with disciplined PR to secure key regulatory outcomes.

Christopher Blake

Corporate Secretary & Director of Global Strategic Relations

Executive Secretariat & Institutional Affairs

Christopher manages the firm's executive secretariat and global institutional relationships. He oversees delegation diplomacy, multilateral accreditation, and high-level forum coordination.

Margaret E. Sullivan

Managing Director, Government Affairs

Oversees federal legislative strategy, appropriations advocacy, and engagement with Congress and executive agencies.

Marcus D. Whitfield

Head of Public Policy

Directs policy research, regulatory analysis, and the development of TSI's white papers and position briefs.

Diane R. Marchetti

Director, Strategic Advocacy

Builds coalitions and issue campaigns that align industry, civil society, and policymakers behind shared objectives.

Karen L. Whitmore

Regional Director, Asia-Pacific — Singapore

Leads TSI's Singapore office, advising on market entry, trade policy, and APEC engagement across the region.

Nathan A. Reyes

Regional Director, Middle East — Riyadh

Heads the Riyadh office, supporting sovereign engagement, investment promotion, and Gulf forum participation.

Patricia G. Lindqvist

Senior Counsel, International Business Facilitation

Advises multinationals on cross-border structuring, compliance, and long-term institutional partnerships.