  It is known that Neutron Stars may be converted into more compact Strange
Stars (SS) on capture/formation of a ``seed'' of strange matter. It is also
known that the binding energy of the nascent hot SS is likely to be radiated as
$\nu -\bar\nu$s so that an electromagnetic pair fireball (FB) may be created by
neutrino annihilation. And already this process has been considered as a
probable source of Gamma Ray Bursts (GRB) by several authors, the most notable
of which is due to Cheng & Dai (PRL, 77, 1210, 1996). They mentioned that this
process may generate a FB luminosity (outside the neutrinosphere) of 10**(49)
erg. But we point out here that a SS is a relativistic object with surface
gravitation z=0.5. Accordingly, we present here a Relativistic Model of this
process, and show that, for a massive SS with M=2 solar mass, one may explain a
GRB energy of ~ 10**(53) erg., which is 4 orders higher than previous
non-relativistic estimate. Further since the baryonic mass of the thin crust of
a strange star is negligible, this FB will generate an extremely relativistic
blast wave. Thus this process may be one of the viable routes for the genesis
of hitherto unexplained cosmic Gamma Ray Bursts. While some of the GRBs might
be beamed, many of them do not show any long term spectral break in their
afterglows and are likely to be quasi-spherical. A particular example is GRB
971214 for which estimated GRB energy is 3. 10**(53) erg. Our model may be
useful for understanding the genesis of such powerful and unexplained bursts.
