Parties are free to determine the number of arbitrators. But if it is an even number, then the arbitrators so appointed shall jointly appoint an "additional arbitrator" who shall act as the Chairman. Where the parties do not determine the number, it shall be three (section 6).

The parties are free to agree on the procedure for appointment. Failing such agreement, the High Court can make the appointment. If the agreed procedure fails, then also, the High Court has power to make the appointment (section 7).