These four priorities represent 44%, 25%, 25% and 6%, respectively, of the total investment. The three partners signed a new treaty on 17 June 2008 in The Hague with a view to pursuing Benelux co-operation and extending cross-border co-operation in the areas of economics, sustainability, justice and the interior. The sustainable development chapter of the Benelux Plan for 2009 calls for concerted action for territorial development, the climate (harmonising measures to promote renewable energies) and nature (Natura 2000).