Symmetry in the Geometry of Metric Contact Pairs
  We prove that the universal covering of a complete locally symmetric normal metric contact pair manifold is a Calabi-Eckmann manifold. Moreover we show that a complete, simply connected, normal metric contact pair manifold such that the foliation induced by the vertical subbundle is regular and reflections in the integral submanifolds of the vertical subbundle are isometries, then the manifold is the product of globally $\phi$-symmetric spaces and fibers over a locally symmetric space endowed with a symplectic pair. 
G. Bande, D. E. Blair
math.DG