Just sell them; you will miss out on the statutory interest accrued during the arbitration proceedings, but otherwise, there are no obstacles to selling.
I can almost guarantee that if you didn’t react in any way to the Affecto and Technopolis tender offers, they went through a similar arbitration process. It is part of the so-called mandatory process when a buyer’s ownership exceeds 90% and the obligation/right to redeem the remaining shares is triggered.