<p>A multistage compressor for supplying compressed gas to a machine and receiving return gas under pressure from the machine for recycling. The compressor comprises at least one rotodynamic compressor stage (10,12) arranged upstream of at least one positive displacement compressor stage (14,16) and a return line (20) connected between stages of the compressor or directed into the blading of the rotodynamic compressor for receiving the return gas from the machine. The return line (20) is connected upstream of the first positive displacement stage (14) of the compressor.</p>
