  We discuss the influence of extragalactic magnetic fields on the intensity of
gamma-ray emission produced in electromagnetic cascades from ultra-high energy
cosmic rays propagating in extragalactic space. Both cosmic rays and cascade
particles propagate mostly out of galaxies, galactic clusters, and large scale
structures as their relative volume is small. Therefore their magnetic fields
weakly affect emission produced in cascades. Yet estimates of this influence
can be useful searching for dark matter particles, when components of
extragalactic gamma-ray background should be known, including cascade gamma-ray
emission. To study magnetic field influence on cascade emission we analyze
cosmic particle propagation in fields of ~10^(-6) and 10^(-12) G (the former is
typical inside galaxies and clusters and the latter is common in voids and
outside galaxies and clusters). The calculated spectra of cascade gamma-ray
emission are similar in the range of ~10^7-10^9 eV. So analyzing cascade
emission in this range it is not necessary to specify models of extragalactic
magnetic field.
