With respect to taxes, fees, charges and to fiscal deductions and exemptions, each Contracting Party shall accord to nationals of the other Contracting Party who are engaged in any economic activity in its territory, treatment not less favourable than that accorded to its own nationals or to those of any third State who are in the same circumstances, whichever is more favourable to the nationals concerned. For this purpose, however, there shall not be taken into account any special fiscal advantages accorded by that Party under an agreement for the avoidance of double taxation, by virtue of its participation in a customs union, economic union or similar institution, or on the basis of reciprocity with a third State.