  Isospin properties of fragments measured in multifragmentation of 136Xe and
124Xe projectiles in mid-peripheral collisions with a lead target at 1 A GeV
were studied within the statistical approach describing the liquid-gas nuclear
phase transition. By analyzing the isoscaling phenomenon and the mean N-over-Z
ratio of the fragments with Z=10-13 we have concluded that the symmetry energy
of hot fragments produced in multifragment environment at subnuclear densities
at high temperatures decreases in comparison with cold nuclei.
