When one of the legal entities referred to in II of Article L. 621-9 is temporarily or permanently banned from trading or temporarily suspended from trading, the Chairman of the Autorité des marchés financiers, after seeking the opinion of the legal entity penalised, shall appoint another such person, with the agreement of the latter, to carry out the activity in question. The mission of the person so appointed expires either at the end of the period of prohibition or suspension, or when there are no longer any open positions on behalf of one of the clients.