  We extend the investigation of general relativistic effects on the observed
X-ray continuum of Kerr black holes in the context of the light bending model
(Miniutti & Fabian, 2004). Assuming a ring-like illuminating source,
co-rotating with the underlying accretion disk, we study the shape and
normalisation of the primary and disc reflected continuum as well as the
dependence of the observed spectrum on the line of sight for various source
heights and radii. These calculations are performed using Monte-Carlo methods
to compute the angle dependent reflection spectrum from the disc. The effects
of general relativity are illustrated by a comparison with Newtonian and
Special Relativity calculations. We find that relativistic distortions can
strongly affect the shape of the reflected spectrum. Light bending can
dramatically increase the observable reflected flux and reduce the primary
emission. In addition, multiple reflections due to the reflected photons
deflected toward the disc can alter significantly the shape of the spectrum
above 10 keV. Large variations of the ring radius at constant height can lead
to an (unobserved) anti-correlation between primary and reflected flux. In
another side, the variability behaviour of several sources can be reproduced if
the ring source radius is small (<5 r_g), and its height varies by a large
factor. In particular, a non-linear flux-flux relation, similar to that
observed in several sources, can be produced. We compare our model with the
flux-flux plot of NGC4051, and find an agreement for low inclination angles
(<20 deg.), ring source radius <3 r_g and a height varying between 0.5 to 10
r_g.
