8, respectively, for the double-lepton triggers, while they are 15, 8 and 5for the triple-electron trigger. Events with at least four well identified and isolated electrons or muons are then selected offline, if they are compatible with being produced at the primary vertex. The primary vertex is selected to be the one with the highest sum of $\pt^2$ of associated tracks. Among all same-flavour and opposite-sign (SFOS) lepton pairs in the event, the one with an invariant mass closest to the nominal $\PZ$ boson mass is denoted $\PZ_{1}$ and retained if its mass, $m(\PZ_1)$, satisfies $40 \le m(\PZ_1) \le 120\GeV$. The remaining leptons are considered and the presence of a second $\ell^{+}\ell^{-}$ pair, denoted $\PZ_{2}$, is required with condition $12 \le m(\PZ_2) \le 120\GeV$. If more than one $\PZ_{2}$ candidate satisfies all criteria, the pair of leptons with the largest sum of the transverse momenta magnitudes, $\Sigma |\pt|$, is chosen. Among the four selected leptons $\ell_{i}$ ($i = 1..4$) forming the $\PZ_{1}$ and $\PZ_{2}$ candidates, at least one lepton should have $\pt \ge 20\GeV$, another one $\pt \ge 10\GeV$, and any opposite-charge pair of leptons $\ell_{i}^{+}$ and $\ell_{j}^{-}$, irrespective of flavor, must satisfy $m({\ell_{i}^{+}\ell_{j}^{-}}) \ge 4\GeV$. The algorithm to recover 