(13)With regard to the scope of activity of management companies and in order to take into account national law and permit such companies to achieve significant economies of scale, it is desirable to permit them also to pursue the activity of management of portfolios of investments on a client-by-client basis (individual portfolio management), including the management of pension funds as well as some specific non-core activities linked to the main business without prejudicing the stability of such companies. However, specific rules should be laid down in order to prevent conflicts of interest when management companies are authorised to pursue the business of both collective and individual portfolio management.