High Quality Content by WIKIPEDIA articles! The State Union of Serbia and Montenegro started the process of Accession to the European Union in November 2005, when negotiations over a Stabilisation and Association Agreement began. In May 2006, Montenegro voted for independence in a referendum and the State Union of Serbia and Montenegro was dissolved. Serbia continued with the existing negotiations, and separate negotiations were launched with Montenegro in September 2006. The Agreement was initialled on 15 March 2007 and officially signed on 15 October 2007.