  Using the NASA Extragalactic Database, we have searched the close environment
of 98 star-forming dwarf galaxies (SFDGs) from field- and low density
environments for companion galaxies. Most of the found companions are dwarf
galaxies, previously disregarded in environmental studies of SFDGs. Using a
subsample at low redshifts, cz < 2000 km/s, i.e. less biased against dwarf
companions, we find that 30% of the SFDGs have close companions within a
projected linear separation s_p < 100 kpc and a redshift difference of (Delta
cz) < 500 km/s. This fraction must be considered a lower limit, given the
incompleteness of the available data sets and the non-negligible frequency of
HI clouds in the vicinity of SFDGs, so that the majority of SFDGs should not be
considered isolated. The redshift differences between companion candidates and
sample SFDGs are typically smaller than ~250 km/s and concentrated towards
lower values. This is similarly observed for dwarf satellites of spiral
galaxies and suggests a physical association between the companion candidates
and the sample SFDGs. SFDGs with a close companion do not show significant
differences in their H(beta) equivalent widths and B-V colours as compared to
isolated ones. However, the available data do not allow to rule out close dwarf
companions as an influencing factor for star formation activity.
