(3)Holders of shares carrying voting rights should be able to exercise those rights given that they are reflected in the price that has to be paid at the acquisition of the shares. Furthermore, effective shareholder control is a pre-requisite to sound corporate governance and should, therefore, be facilitated and encouraged. It is therefore necessary to adopt measures to approximate the laws of the Member States to this end. Obstacles which deter shareholders from voting, such as making the exercise of voting rights subject to the blocking of shares during a certain period before the general meeting, should be removed. However, this Directive does not affect existing Community legislation on units issued by collective investment undertakings or on units acquired or disposed of in such undertakings.