  We propose an approximate description of basic parameters (radius, mass and
oblateness) of general relativistic compact rotating objects in terms of the
parameters of the static configuration and of the angular velocity only. The
representation in terms of static properties is derived using the condition of
stationary equilibrium together with some phenomenological assumptions. The
predicted radius and mass of rotating neutron star (described by some realistic
equations of state) and strange star (described by the bag model equation of
state) are compared with data obtained by numerical integration of
gravitational field equation. The obtained formulae also allow a simple
derivation of the "empirical" equation relating the maximum rotation frequency
$\Omega_{max}$ of uniformly rotating star models to the mass and radius of the
maximum allowable mass configuration of the non-rotating model.
