Pinsent Masons hires investor-state arbitration specialist in London

01 Mar 2023 | 09:50 am | 1 min. read

Multinational law firm Pinsent Masons has hired partner Sylvia Tonova to the firm’s International Arbitration Practice.

Sylvia is a highly experienced international arbitration lawyer and has extensive experience in both international commercial and investment treaty arbitration focussing on complex, high-value disputes, often in the context of high-profile and politically sensitive projects and transactions. Sylvia will co-lead the firm’s investor-state dispute settlement and public international law team.

She is dual qualified in England and the US (New York and Washington DC).  Sylvia represents clients under all the major arbitration rules and advises clients on investment treaty disputes, sovereign immunity, and managing political risk.

Sylvia joins from Jones Day where she has led on arbitrations in Europe, the Middle East, Africa, Latin America, and Asia. She also sits as an arbitrator and was appointed to the ICSID Panel of Arbitrators for a six-year term in 2016.

Jason Hambury, global co-head of Pinsent Masons’ International Arbitration Practice, said: “Sylvia’s skillset is a perfect fit with our leading arbitration practice. Our clients will benefit from her experience working on complex cross-border commercial and investor-state disputes, across numerous sectors, such as energy, mining and telecoms. Sylvia will play a significant role in the continued success of our practice and we are delighted to welcome her.”

Sylvia has been recognised in Legal 500, Who’s Who Legal and Chambers as being a leading individual in international arbitration.

Sylvia said of her appointment: “I am thrilled to join Pinsent Masons and co-lead the investor-state dispute settlement and public international law team. Investment treaty law plays a pivotal role in the political risk strategy of cross-border investors, particularly in the energy, mining and infrastructure sectors. I look forwarding to helping clients resolve their politically sensitive disputes and joining a team highly regarded for its deep sector knowledge and world-class reputation in handling high-value, complex arbitrations.”

Latest press releases

Show me all press releases

Pinsent Masons part of consortium appointed to advise Nuclear Waste Services on UK Geological Disposal and Waste Repository Projects

Pinsent Masons, Burges Salmon and Herbert Smith Freehills Kramer have been appointed to support Nuclear Waste Services (NWS) in relation to the planning, consenting and regulatory work associated with the UK’s Geological Disposal Facility and Low Level Waste Repository. 

Pinsent Masons completes move into new Sydney office

Multinational law firm Pinsent Masons has today launched its second decade in Australia by completing its move into new offices at 33 Alfred Street in Sydney.

Pinsent Masons announces double corporate partner hire to London capital markets team

International law firm Pinsent Masons has today announced that it has strengthened its City practice with the hire of two senior corporate partners, Nicholas Holmes from Ashurst and Dinesh Banani from Herbert Smith Freehills Kramer.

People who viewed this press release also viewed

Show me all press releases

Pinsent Masons part of consortium appointed to advise Nuclear Waste Services on UK Geological Disposal and Waste Repository Projects

Pinsent Masons, Burges Salmon and Herbert Smith Freehills Kramer have been appointed to support Nuclear Waste Services (NWS) in relation to the planning, consenting and regulatory work associated with the UK’s Geological Disposal Facility and Low Level Waste Repository. 

Pinsent Masons advises International Finance Corporation on milestone Bhutan investment

Multinational law firm Pinsent Masons has advised International Finance Corporation (IFC), the largest global development institution focused on the private sector in emerging markets, on its first ever investment in Bhutan’s energy and infrastructure sectors.

Pinsent Masons advises Heidelberg Materials UK on first decarbonised cement production project

Multinational law firm Pinsent Masons has advised Heidelberg Materials UK on securing the funding agreement with UK government to drive forwards its world-leading project to develop a carbon capture and storage (CCS) plant at its Padeswood cement works in North Wales.

For all media enquiries, including arranging an interview with one of our spokespeople, please contact the press office on

+44 (0)20 7418 8199 or 

Location contacts

We are processing your request. \n Thank you for your patience. An error occurred. This could be due to inactivity on the page - please try again.