  We suggest to consider conformal factor dynamics as applying to composite
boundstates, in frames of the $1/N$ expansion. In this way, a new model of
effective theory for quantum gravity is obtained. The renormalization group
(RG) analysis of this model provides a framework to solve the cosmological
constant problem, since the value of this constant turns out to be suppressed,
as a result of the RG contributions. The effective potential for the conformal
factor is found too.
