  Let $\overline{\mathfrak{S}}_\infty$ denote the set of all bijections of
natural numbers. Consider the action of $\overline{\mathfrak{S}}_\infty$ on a
measure space $\left( X,\mathfrak{M},\mu \right)$, where $\mu$ is
$\overline{\mathfrak{S}}_\infty$-quasi-invariant measure. We prove that there
exists $\overline{\mathfrak{S}}_\infty$-invariant measure equivalent to $\mu$.
