  We investigate the gravitational behavior of spherical domain walls (bubbles)
arising during the phase transitions in the early Universe. In the thin-wall
approximation we show the existence of the new solution of Einstein equations
with negative gravitational mass of bubbles and the reversed direction of time
flow on the shell. This walls exhibit gravitational repulsion just as the
planar walls are assumed to do. The equilibrium radius and critical mass of
such objects are found for realistic models.
