We have measured the magnetoresistance and the magnetic phase boundaries T,(B) of mesoscopic superconducting structures containing an A1 loop. The structures were designed to study the nonlocal interaction between the loop and the electrical leads connected to it. Several voltage probes have been attached to the current leads to monitor the superconducting transitions of both the loop and the segments of the leads. Strong coupling effects have been found between the loop and the leads. At low

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... gnetic fields, T, ( B ) of the lead segments reveals a pronounced oscillatory component, while the oscillation amplitude of T,(B) of the loop is significantly reduced when compared to the usual Little-Parks effect. The coupling strength seems to be controlled by the temperaturedependent superconducting coherence length.