  An accurate determination of the Higgs decay branching ratios to bb, cc, gg,
WW* and tau tau pairs is important for the study of the Higgs couplings and for
determining its SM or MSSM nature in the mass range 100 GeV/c2 < M_H < 140
GeV/c^2. This measurement also represents an important benchmark for the
optimisation of the detector design. The accuracy on the determination of the
Higgs decay branching ratio to fermions and WW* pairs has been studied using
the simulation of the detector designed for the TESLA e+e- linear collider at
c.m. energy of 350 GeV and 500 GeV. The results are discussed in terms of the
ability of discriminating between the SM and a MSSM neutral Higgs boson and of
the predictivity on the A boson mass in the MSSM scenario.
