  The influence of external magnetic field $h$ on a static conductivity of
Mott-Hubbard material which is described by model with correlated hopping of
electrons has been investigated. By means of canonical transformation the
effective Hamiltonian which takes into account strong intra-site Coulomb
repulsion and correlated hopping is obtained. Using a variant of generalized
Hartree-Fock approximation the single-electron Green function and quasiparticle
energy spectrum of the model have been calculated. The static conductivity
$\sigma$ has been calculated as a function of $h$, electron concentration $n$
and temperature $T$. The correlated hopping is shown to cause the electron-hole
asymmetry of transport properties of narrow band materials.
