  We consider embeddings of the Virasoro algebra into other Virasoro algebras
with different central charges. A Virasoro algebra with central charge c
(assumed to be a positive integer) and zero mode operator L_0 can be embedded
into another Virasoro algebra with central charge one and zero mode operator c
L_0. We point out that this provides a new route to investigate the black hole
entropy problem in 2+1 dimensions.
