  We discuss the consequences of the charge, parity, time and mass (CPTM)
extended reversal symmetry for the problems of the vacuum energy density and
value of the cosmological constant. The results obtained are based on the
framework with the separation of extended space-time of the interest on the
different regions connected by this symmetry with the action of the theory
valid for the full space-time and symmetrical with respect to the extended CPTM
transformations. The cosmological constant is arising in the model due the
gravitational interactions between the different parts of the space-time trough
the quantum non-local vertices. It is proposed that the constant's value
depends on the form and geometry of the vertices which glue the separated parts
of the extended solution of Einstein equations determining in turn it's
classical geometry. The similarity of the proposed model to the bimetric
theories of gravitation is also discussed.
