User blog comment:-merlin12/Series 6/@comment-95.10.153.161-20121225145159

I found this

According to Claude Albouze, Production Director of Merlin in France: “There will certainly be a S6 of Merlin, it’s just a matter of negotiations because the first contract was signed for a period of five years and has to be renewed, he assures that both BBC and Shine absolutely want a S6 of Merlin, they want it desperately, they both want to continue the adventure”. They are just like us guys, they want a S6!

source:http://merlin.chibichiii.nl/the-merlin-cast/good-news-season-6-merlin/