Sultan specialises in international arbitration and, in particular in state/investor disputes. He has worked on a wide variety of high value and complex arbitration cases, under the rules of the London Court of International Arbitration, the International Chamber of Commerce, UNCITRAL, International Centre for Settlement of Investment Disputes (ICSID), as well as ad hoc multi-party arbitrations involving issues of expropriation, breaches of fair and equitable treatment and denial of justice.