Mr Sum concentrates his practice in all areas of dispute resolution, specialising in China-related matters, cross-border disputes, complex commercial disputes, international trade, insurance and reinsurance, product liability and product recall, with specific focuses on arbitration, litigation, mediation and investigations. Mr Sum is qualified as a solicitor in Hong Kong, England and Wales, and Australia and sits on the panels of arbitrators of various institutions, acting as both counsel and arbitrator in many proceedings. Apart from being an experienced international arbitrator, he is also an accredited mediator of the Hong Kong Mediation Accreditation Association Limited (HKMAAL), China International Economic and Trade Arbitration Commission (CIETAC), and The Law Society of Hong Kong. Mr Sum is the immediate past chairman of the International Chamber of Commerce: Arbitration and ADR Sub-Committee and a director of the eBRAM International Online Dispute Resolution Centre and Vis East Moot Foundation. In addition to serving on the Hong Kong Mediation Council, the Hong Kong Government Advisory Committee on the Promotion of Arbitration, and the Steering Committee on Mediation, Mr Sum has been appointed as an investor-State mediator under the Mainland and Hong Kong Closer Economic Partnership Arrangement (CEPA).