21. If the parties do not come to an agreement, the president shall notify them that he is referring the dispute to arbitration.
The parties have 10 days after they receive the notice to select an arbitrator. If the parties fail to agree on an arbitrator, the president shall appoint an arbitrator ex officio and fix his fees. Every arbitrator appointed ex officio shall be chosen from a list established every five years by the president after consulting the Minister of Transport. The president may, in the same manner, amend the list at any time.
The president shall also appoint the clerk.