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Clifford Chance

Clifford Chance
Sean Marriott

Sean Marriott


Sean Marriott

Sean is an Engineer and Lawyer, and is a Counsel in Clifford Chance's Perth office. Sean is dual qualified (Australia and England & Wales), and specialises in international arbitration, including construction and energy and resources disputes, ISDS (Investor-State Arbitration), maritime disputes and all forms of ADR.

Sean was awarded International ADR Practitioner of the Year 2022 (at the Australian ADR Awards) and is a Member of the ICC Commission on Arbitration and ADR, a Fellow of CIArb (Chartered Institute of Arbitrators) and a Fellow of ACICA (Australian Centre for International Commercial Arbitration). Sean is also a Member of SoCLA (Society of Construction Law Australia).

Sean has acted as managing counsel and advocate in construction, oil and gas, mining, power and renewables disputes, including under ICSID, ICC, LCIA, UNCITRAL and LMAA rules.

Sean also has significant litigation experience, including in the Technology and Construction Court and Commercial Court and Court of Appeal in London.

Sean regularly presents and teaches, and publishes articles and presents seminars on key international arbitration topics, and also on related international law and construction law issues.

Sean has acted for:

  • Global oil & gas contractor in two related international arbitrations arising out of:
    • a design and construction contract for an LNG loading jetty in Western Australia (UNCITRAL Rules, Perth seat; Western Australian governing law)
    • a consortium agreement for the construction of the same LNG loading jetty (ICC Rules, Singapore seat; Western Australian governing law)
  • Power Supplier in an arbitration against an iron ore mine operator concerning supply interruptions, operations and maintenance obligations, compliance with industry technical standards, construction delays, and misrepresentation in relation to network design requirements and responsibility.
  • Australian mining company in an ICSID arbitration against the Arab Republic of Egypt under the Australia-Egypt BIT
  • Oil and gas operator in an UNCITRAL arbitration against construction contractor concerning variations and delays to the completion of the operator's head office and offshore control centre.
  • Lead contractor against subcontractor in an international arbitration concerning losses arising from delays in the construction of a first commercial production oil and gas facility in the Middle East, including issues of work sequencing and schedule management.

News and client work

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Contact details

Career and qualifications

  • University of Sheffield (B.Eng.) 2000
  • Admitted as a solicitor in England & Wales 2010
  • Clyde & Co LLP (Associate) 2010
  • Joined Clifford Chance 2016
  • Senior Associate Clifford Chance 2017
  • Counsel Clifford Chance 2019
  • Admitted as a solicitor in Western Australia 2019

Professional bodies

  • Fellow of the Chartered Institute of Arbitrators
  • Fellow of ACICA (Australian Centre for International Commercial Arbitration)
  • Member of the ICC Commission on Arbitration and ADR
  • Member of the Society of Construction Law Australia

Awards and citations

  • International ADR Practitioner of the Year 2022
    ADR Awards - Australian Disputes Centre