  The underscreened Kondo effect is studied within a model of two impurities
S=1 interacting with the conduction band and via an interimpurity coupling
$K\vec{S_1}.\vec{S_2}$. Using a mean-field treatment of the bosonized
Hamiltonian, we show that there is no phase transition, but a continuous
cross-over versus K from a non Kondo behaviour to an underscreened Kondo one.
For a small antiferromagnetic coupling (K>0), a completely asymmetric situation
is obtained with one s=${1/2}$ component strongly screened by the Kondo effect
and the other one almost free to yield indirect magnetism, which shows finally
a possible coexistence between a RKKY interaction and a local Kondo effect, as
observed in Uranium compounds such as $UPt_3$.
