  This talk presents results of our study of heavy-to-light transition form
factors extracted with the help of light-cone sum rules. We employ a model with
scalar particles interacting via massless-boson exchange and study the
heavy-to-light correlator, relevant for the extraction of the transition form
factor. We calculate this correlator in two different ways: by making use of
the Bethe-Salpeter wave function of the light bound state and by making use of
the light-cone expansion. This allows us to calculate the full correlator and
separately the light-cone contribution to it. In this way we show that the
off-light cone contributions are not suppressed compared to the light-cone one
by any large parameter. Numerically, the difference between the value of the
form factor extracted from the full correlator and from the light-cone
contribution to this correlator is found to be about 20-30% in a wide range of
masses of the particles involved in the decay process.
