Article 18
1. The arbitral tribunal may rule in respect of its own jurisdiction and, for this purpose, may examine the validity of the arbitration agreement.
2. A ruling that the contract is invalid shall not entail ipso jure the nullity of the arbitration agreement contained in it.
3. The arbitral tribunal's ruling that it has jurisdiction may not be contested before the judicial authority except at the same time as the award on the main issue and by the same procedure. The judicial authority may at the request of one of the parties decide whether a ruling that the arbitral tribunal has no jurisdiction is well founded.
4. The appointment of an arbitrator by a party shall not deprive that party of his rights to challenge the jurisdiction of the arbitral tribunal.
Article 19
1. The parties may, up to the time of acceptance of office by the first arbitrator, settle the period within which the award is to be made or provide for a method according to which the period is to be settled.
2. If the parties have not prescribed a period or a method of prescribing a period, if the arbitral tribunal delays in making the award and if a period of six months has elapsed from the date on which all the arbitrators accepted office in respect of the dispute submitted to arbitration, the judicial authority may, at the request of one of the parties, stipulate a period for the arbitral tribunal.
3. The office of arbitrator shall terminate if the award is not made within the relevant period unless that period is extended by agreement between the parties.
4. Where arbitrators are named in the arbitration agreement and the award is not made within the relevant period, the arbitration agreement shall terminate ipso jure, unless the parties have agreed otherwise.
Article 20
Except where otherwise stipulated, an arbitral tribunal may make a final award in the form of one or more awards.
Article 21
Except where otherwise stipulated, arbitrators shall make their awards in accordance with the rules of law.