Just six months after Blackberry maker Research in Motion awarded its creative business to MDC-owned 72andSunny and BBDO Worldwide, our sources familiar with the matter confirm that the former agency will no longer be working with the brand. It appears, however, that the relationship between RIM and BBDO Worldwide–particularly AMV BBDO, which leads creative for RIM outside the U.S.–will remain intact.

In terms of 72andSunny and RIM, from what we hear, there was a difference in opinion on how to position the PlayBook tablet, which led to the parting of ways. We expect to know more next week. Suffice to say, though, it’s been a rough patch for RIM, which just lost its top digital marketer Brian Wallace to Samsung and saw its shares fall today by 20 percent.