  In this paper we consider Lie superalgebras decomposable as the sum of two
proper subalgebras. Any of these algebras has the form of the vector space sum
$L=A+B$ where $A$ and $B$ are proper simple subalgebras which need not be
ideals of $L$, and the sum need not be direct.
  The main result of this paper is the following: Let $S = {osp}(m,2n)$ be a
Lie superalgebra such that $S=K+L$ where $K$, $L$ are two proper basic simple
subalgebras. Then $m$ is even, $m=2k$ and $K \cong osp(2k-1,2n)$, $L \cong
sl(k,n)$.
