  We investigate homogeneous and isotropic cosmological models in scalar-tensor
theories of gravity where two scalar fields are nonminimally coupled to the
geometry. Exact solutions are found, by Noether symmetries, depending on the
form of couplings and self-interaction potentials. An interesting feature is
that we deal with the Brans-Dicke field and the inflaton on the same ground
since both are nonminimally coupled and not distinguished {\it a priori} as in
earlier models. This fact allows to improve dynamics to get successful extended
inflationary scenarios. Double inflationary solutions are also discussed.
