For the purposes of this Directive the following definitions shall apply:

(a) "company of a Member State" means any company which: (i) takes one of the forms listed in Annex I, Part A; (ii) according to the tax laws of a Member State is considered to be resident in that Member State for tax purposes and, under the terms of a double taxation agreement concluded with a third State, is not considered to be resident for tax purposes outside the Union; (iii) moreover, is subject to one of the taxes listed in Annex I, Part B, without the possibility of an option or of being exempt, or to any other tax which may be substituted for any of those taxes;

(b) "permanent establishment" means a fixed place of business situated in a Member State through which the business of a company of another Member State is wholly or partly carried on in so far as the profits of that place of business are subject to tax in the Member State in which it is situated by virtue of the relevant bilateral tax treaty or, in the absence of such a treaty, by virtue of national law.