Holomorphic GL(2)-geometry on compact complex manifolds

We study holomorphic GL(2) and SL(2) geometries on compact complex manifolds. We show that a compact K"ahler manifold of complex even dimension higher than two admitting a holomorphic GL(2)-geometry is covered by a compact complex torus. We classify compact K"ahler-Einstein manifolds and Fano manifolds bearing holomorphic GL(2)-geometries. Among the compact K"ahler-Einstein manifolds we prove that the only examples bearing holomorphic GL(2)-geometry are those covered by compact complex tori, the three dimensional quadric and those covered by the three dimensional Lie ball (the non compact dual of the quadric).