  Using perturbative renormalization group we study the influence of random
velocity field on the critical behaviour of directed bond percolation process
near its second-order phase transition between absorbing and active phase. We
consider Kraichnan model with finite correlation time for modelling advecting
velocity field. Using functional integral representation we are able to apply
field-theoretic renormalization group to determine possible universality
classes. The model is analyzed near its critical dimension by means of
three-parameter expansion in $\epsilon,\delta,\eta$, where $\epsilon$ is the
deviation from the Kolmogorov scaling, $\delta$ the deviation from the critical
space dimension $d_c$ and $\eta$ is the deviation from the parabolic dispersion
law for the velocity correlator. Fixed points with corresponding regions of
stability are evaluated to the leading order in the perturbation scheme.
