  We search for non-trivial relativistic solutions of the hydrodynamic
equations with quasi-inertial flows such as in the Bjorken-like models. The
problem is analyzed in general and the known results are reproduced by a method
proposed. A new class of 3D anisotropic analytic solutions with quasi-inertial
property is found. An ellipsoidal generalization of the spherically symmetric
Hubble flow with constant pressure is proposed as a particular case. The
relativistic expansion of finite systems into vacuum is also described within
this class. A region of applicability and possible utilization of the new
solutions for processes of A+A collisions is discussed.
