(4) In view of the continuing dependence of many less developed Parties on the export of a limited range of primary products, it is necessary to create more favourable and acceptable conditions of access for these products and, where appropriate, to develop measures to stabilise and improve the conditions of the world markets for these products, including measures to achieve stable, fair and remunerative prices that allow for an expansion of world trade and demand, as well as a dynamic and steady growth in the real export earnings of these countries, in order to provide them with increasing resources for their economic development. (a) as regards a customs union or an interim agreement leading to the formation of a customs union, customs duties and other related measures imposed on the establishment of such a Union or on an interim arrangement for trade with parties which are not parties to the Union or to the Agreement may not be overall superior to or restrictive than the general impact of customs and trade procedures; the constituent territories before the formation of such a Union or the adoption of such an interim agreement; 8. The Parties recognise that the Contracting Parties covered by paragraph 4 (a) of this Article have a rapidly developing tendency to encounter balance of payments difficulties resulting mainly from efforts to develop their internal markets and the instability of their terms of trade. (iii) consultations between the Parties could also, where appropriate, cover an agreement on joint action to promote the objectives of this Agreement, in accordance with Article XXV(1). (f) so that the Contracting Parties may allow the less developed Parties to take specific measures to promote their trade and development; (a) in cases where a Government fixes, directly or indirectly, the resale price of goods manufactured whoin whole or mainly in the territory of less developed Parties, do everything in its power to maintain trade margins at an equitable level; 11. . . .