  Let $\sigma=(\sigma_{1},\sigma_{2},\dots,\sigma_{n})\in \mathbb{S}^{n-1}$ and
$d\sigma$ denote the normalised Lebesgue measure on $\mathbb{S}^{n-1},~n\geq
2$. For functions $f_1, f_2,\dots,f_n$ defined on $\R$ consider the multilinear
operator given by
$$T(f_{1},f_{2},\dots,f_{n})(x)=\int_{\mathbb{S}^{n-1}}\prod^{n}_{j=1}f_{j}(x-\sigma_j)d\sigma,
~x\in \R.$$ In this paper we obtain necessary and sufficient conditions on
exponents $p_1,p_2,\dots,p_n$ and $r$ for which the operator $T$ is bounded
from $\prod_{j=1}^n L^{p_j}(\R)\rightarrow L^r(\R),$ where $1\leq p_j,r\leq
\infty, j=1,2,\dots,n.$ This generalizes the results obtained
in~\cite{jbak,oberlin}.
