  We present a new model describing strongly correlated electrons on a general
$d$-dimensional lattice. It differs from the Hubbard model by interactions of
nearest neighbours, and it contains the $t$-$J$ model as a special case. The
model naturally describes local electron pairs, which can move coherently at
arbitrary momentum. By using an $\eta$-pairing mechanism we can construct
eigenstates of the hamiltonian with off-diagonal-long-range-order (ODLRO).
These might help to relate the model to high-$T_c$ superconductivity. On a
one-dimensional lattice, the model is exactly solvable by Bethe Ansatz.
