June 30 [16:00 EDT] -- The Philadelphia R&B chart-topping quintet Az Yet has just become a quartet with the departure of Marc Nelson.

The group's manager told MTV News that Nelson was ousted due to "personality conflicts and creative differences," but would not elaborate any further. Spokespeople for the group, which is currently charting with "Hard For Me To Say I'm Sorry," say that Nelson will remain friends with the rest of the group, and that his split with them is amicable.

Nelson will now concentrate on songwriting and producing, and in the past, he has worked in this behind-the-scenes capacity with Toni Braxton and Aaron Neville.

During Nelson's time with Dion Allen, Darryl Anthony, Shawn Rivera, and Kenny Terry, the group attained gold sales status with its self-titled debut album.

Az Yet will press on, and will follow up their current hit single with "That's All I Want." The group's manager says that for now Az Yet will tour as a quartet, but eventually hopes to replace Nelson.

Nelson was brought into the group in early 1996, five year's after its formation. Nelson is also a former member of another Philadelphia-based group, Boyz II Men, which he left prior to the group¹s 1991 debut album.