Let A be an F-central simple algebra of degree m2 =
and G be a subgroup of the unit group
of A such that F[G] = A. We prove that if G is a central product of two of its subgroups M and N, then
F[M] ⊗F F[N] F[G]. Also, if G is locally nilpotent, then G is a central product of subgroups Hi, where
[F[Hi] : F] = p2αi
i , A = F[G] F[H1] ⊗F · · · ⊗F F[Hk] and Hi/Z(G) is the Sylow pi-subgroup of G/Z(G)
for each i with 1 ≤ i ≤ k. Additionally, there is an element of order pi in F for each i with 1 ≤ i ≤ k.