  The mass matrices of the charged leptons and neutrinos, previously derived in
a minimal S_3-invariant extension of the Standard Model, were reparametrized in
terms of their eigenvalues. We obtained explicit, analytical expressions for
all entries in the neutrino mixing matrix, V_PMNS, the neutrino mixing angles
and the Majorana phases as functions of the masses of charged leptons and
neutrinos in excellent agreement with the latest experimental values. The
resulting V_PMNS matrix is very close to the tri-bimaximal form of the neutrino
mixing matrix. We also derived explicit analytical expressions for the matrices
of the Yukawa couplings and computed the branching ratios of some selected
flavour changing neutral current processes as functions of the masses of the
charged leptons and the neutral Higgs bosons. We find that the S_3 x Z_2
flavour symmetry and the strong mass hierarchy of the charged leptons strongly
suppress the FCNC processes in the leptonic sector well below the present
experimental upper bounds by many orders of magnitude.
