  The branching fraction of the decay $B_{s}^{0} \rightarrow
D_{s}^{(*)+}D_{s}^{(*)-}$ is measured using $pp$ collision data corresponding
to an integrated luminosity of $1.0fb^{-1}$, collected using the LHCb detector
at a centre-of-mass energy of $7$TeV. It is found to be \begin{align*}
  {\mathcal{B}}(B_{s}^{0}\rightarrow~D_{s}^{(*)+}D_{s}^{(*)-}) = (3.05 \pm 0.10
\pm 0.20 \pm 0.34)\%, \end{align*} where the uncertainties are statistical,
systematic, and due to the normalisation channel, respectively. The branching
fractions of the individual decays corresponding to the presence of one or two
$D^{*\pm}_{s}$ are also measured. The individual branching fractions are found
to be \begin{align*}
  {\mathcal{B}}(B_{s}^{0}\rightarrow~D_{s}^{*\pm}D_{s}^{\mp}) = (1.35 \pm 0.06
\pm 0.09 \pm 0.15)\%,
  \newline{\mathcal{B}}(B_{s}^{0}\rightarrow~D_{s}^{*+}D_{s}^{*-}) = (1.27 \pm
0.08 \pm 0.10 \pm 0.14)\%. \end{align*} All three results are the most precise
determinations to date.
