Associate

Siobhan Neill

Languages

English

Social media

Siobhan Neill is an associate in CMS’ London office specialising in contentious and advisory matters relating to the oil and gas and power sectors.

Siobhan acts for energy companies, construction and engineering companies and contractors on a broad range of issues, and is experienced in high-value international arbitration (UNCITRAL, LCIA, ICC, LMAA), commercial litigation (including the Court of Appeal), judicial review and expert determination.

Relevant experience

Octopus Energy as an interested party in a judicial review challenge related to the transaction by which Octopus Energy acquired Bulb Energy from administration (R (British Gas Trading and E.ON) v Secretary of State for Energy Security and Net Zero [2025] EWCA Civ 209).
An international energy company in a USD 90m LCIA and ICC arbitrations concerning different licence agreements for seismic data in Africa in relation to the ‘change of control’ provisions.
A Brazilian energy company in an LCIA arbitration regarding the operation and maintenance of a floating production storage and offloading vessel.
An independent power producer in a USD 400m plus ICC arbitration in relation to termination and force majeure issues arising out of a long-term gas purchase agreement.
A Spanish contractor on a dispute in relation to an EPC contract in connection with an offshore windfarm.
The world’s first gas power station with carbon capture and network for transporting and offshore storage of carbon.
An offshore drilling contractor in an LMAA arbitration against a South Korean shipbuilder in relation to a USD 500m claim for delay, additional costs and expenses incurred in the construction of four semi-submersible rigs, including a significant counterclaim for approximately USD 150m.
The Commercial Court on Single Buoy Moorings Inc v Aspen Insurance UK Limited [2018] EWHC 1763 in relation to disclosure and privilege, in the context of a USD 1.5bn dispute concerning a mobile offshore production unit in the North Sea.
A major oilfield services contractor in respect of the potential termination of three contracts worth approximately USD 250m relating to the provision of integrated exploration, appraisal and drilling services in India.

Memberships & Roles

Member, Energy Arbitration Club.
Member, American Institute of Petroleum Negotiators.

Education

2017 - Legal Practice Course, BPP University London, London.
2014 - International Legal Studies (LLB), University of Southampton and the University of Hong Kong.

Practice Areas

Energy Disputes Construction & Engineering Disputes International Arbitration Judicial Review Energy and Climate Change

sectors

Energy & Climate Change Energy Networks Offshore and Onshore Wind Oil & Gas Power Projects Power Regulation

Insights

Global Reach

UK Pay Gap Report 2024