Be careful if you have shares in companies quoted on Euronext, as unlike the more established markets, there are no market makers which match buyers with sellers for a price (usually close to the market price).
EURONEXT sells shares on an auction based system, which means you simply offer the shares for sale, and see if anyone makes an offer to buy. If no offers are forthcoming or at the right price, you cannot sell the shares, and so selling the same quickly simply cannot be done, and you can be forced to lower the price to a level well below the “market” price in order to attract buyers.