  The periodic Anderson model is extended by switching on a Hubbard U for the
conduction electrons. We use the Gutzwiller variational method to study the
nearly integral valent limit. The lattice Kondo energy contains the U-dependent
chemical potential of the Hubbard subsystem in the exponent, and the
correlation-induced band narrowing in the prefactor. Both effects tend to
suppress the Kondo scale, which can be understood to result from the blocking
of hybridization. At half-filling, we find a Brinkman-Rice-type transition from
a Kondo insulator to a Mott insulator.
