Mixed metric 3-contact manifolds and paraquaternionic K\"ahler manifolds

We study manifolds endowed with mixed metric 3--contact structures, proving that the distribution spanned by the Reeb vector fields is integrable, with totally geodesic integral manifolds, of constant sectional curvature $k=\pm1$. We also prove a result of projectability of such structures onto paraquaternionic K\"ahlerian structures.