  We propose the scheme implementing partial deterministic non-demolition Bell
measurement. When it is used in quantum teleportation the information about an
unknown input state is optimally distributed among three outgoing qubits. The
optimality means that the output fidelities saturate the asymmetric cloning
inequality. The flow of information among the qubits is controlled by the
preparation of a pair of ancillary qubits used in the Bell measurement. It is
also demonstrated that the measurement is optimal two-qubit operation in the
sense of the trade-off between the state disturbance and the information gain.
