The following shall be substituted for Article 59 of Directive 78/660/EEC:
1. A Member State may require or permit that participating interests, as defined in Article 17, in the capital of undertakings over the operating and financial policies of which significant influence is exercised, be shown in the balance sheet in accordance with paragraphs 2 to 9 below, as sub-items of the items "shares in affiliated undertakings" or "participating interests", as the case may be. An undertaking shall be presumed to exercise a significant influence over another undertaking where it has 20 % or more of the shareholders' or members' voting rights in that undertaking. Article 2 of Directive 83/349/EEC shall apply.
2. When this Article is first applied to a participating interest covered by paragraph 1, it shall be shown in the balance sheet either:
(a) at its book value calculated in accordance with Articles 31 to 42. The difference between that value and the amount corresponding to