We evaluate the second--order (beyond--mean--field) contribution to the
equation of state of nuclear matter with the effective Skyrme force and use
cutoff and dimensional regularizations to treat the ultraviolet divergence
produced by the zero--range character of this interaction. An adjustment of the
force parameters is then performed in both cases to remove any double counting
generated by the explicit computation of beyond--mean--field corrections with
the Skyrme force. In addition, we include at second order the rearrangement
terms associated to the density--dependent part of the Skyrme force and discuss
their effect. Sets of parameters are proposed to define new effective forces
which are specially designed for second--order calculations in nuclear matter.Comment: 29 figures, 9 table