  We have analyzed the quantum interference effects in the macroscopic
''superconducting molecule''. The composite system consists of two massive
superconducting rings, each interrupted by a Josephson junction, which are at
the same time weakly coupled with one another. The special case of coupling via
the Josephson four-terminal junction is considered. The structure of the
macroscopic quantum states in an applied magnetic field is calculated. It is
shown, that depending on the values of the magnetic fluxes through each ring,
the system displays two groups of states, the ''orthostates'' with both induced
currents going in the same direction, and the ''parastates'' with the opposite
currents and with the total induced flux locked to zero value. The transition
to the flux locked state with changing of the total applied flux is sudden and
is preserved in a certain interval which is determined by the difference of the
fluxes applied through each ring. It makes the system sensitive to small
gradients of the external magnetic field.
