(1) The arbitral tribunal is to decide on the dispute in accordance with the legislative provisions the parties have designated as being applicable to the substance of the legal dispute. Unless the parties expressly have agreed otherwise, the designation of the laws or the legal system of a given state is to be understood as directly referring to the rules of substantive law of that state, and not to its conflict of laws rules.
(2) Absent a designation of the applicable legislative provisions by the parties, the arbitral tribunal is to apply the law of that state with which the subject matter of the proceedings is most closely connected.
(3) The arbitral tribunal is to take its decision based on a consideration of what is fair and equitable only if the parties have expressly authorised it to do so. The authorisation may be granted up until the time the arbitral tribunal takes such decision.
(4) In all cases, the arbitral tribunal is to decide in accordance with the terms of the contract and is to take into account any usages of the trade that may be applicable to the transaction.