  Let H be a spherical subgroup of minimal rank of the semisimple simply
connected complex algebraic group G. We define some functions on the
homogeneous space G/H that we call generalised spherical minors. When G = H x
H, we recover Fomin-Zelevinsky generalised minors. We prove that generalised
spherical minors satisfy some integer coefficients polynomial relations, that
extend the identities of classical generalised minors due to Fomin and
Zelevinsky, and that have the shape of exchange relations of LP-algebras.
