We show that under particular circumstances a general relativistic spherica
lly symmetric bounded distribution of matter could satisfy a non-local equa
tion of state. This equation describes, at a given point, the components of
the corresponding energy-momentum tensor not only as a function at that po
int, but as a functional throughout the enclosed configuration. We have fou
nd that these types of dynamic bounded matter configurations, with constant
compactness or gravitational potentials at the surface, admit a conformal
Killing vector field and fulfil the energy conditions for anisotropic imper
fect fluids. We present several analytical and numerical models satisfying
these equations of state which collapse as reasonable radiating anisotropic
spheres in general relativity.