A method for low-speed balancing of a rotor having at least one compressor stage blades assembly , the compressor stage blades assembly having a row of compressor blades circumferentially clamped and supported by one or more rotor discs to form a stage of a compressor section for a gas turbine engine , and wherein the compressor stage blades assembly includes a circumferential clearance , the method comprising: - identifying a plurality of compressor blades in the compressor stage blades assembly as located blades , wherein each located blade has an angular position with respect to an axis of rotation of the compressor stage blades assembly ; - maintaining the located blades in their respective angular positions within the compressor stage blades assembly such that the located blades divide the compressor stage blades assembly into a plurality of sectors , wherein each sector comprises one or more movable blades and wherein the circumferential clearance is subdivided into sectoral circumferential clearances ; - circumferentially adjusting the movable blades , for each sector , such that the sectoral circumferential clearance within the sector is moved circumferentially downstream relative to the movable blades and with respect to a direction of rotation of the compressor stage blades assembly when the compressor stage blades assembly is rotated; - introducing one or more inserts in each of the sectoral circumferential clearances to maintain relative positions of the sectoral circumferential clearance and the movable blades within each sector ; and characterized by - rotating the rotor up to 20% of a maximum rotational speed of the rotor, - determining a measure of unbalance for the rotor with the compressor stage blades assembly in low-speed balancing conditions; - balancing the compressor stage blades assembly ; and - removing the one or more inserts after low-speed balancing has been completed. - identifying a plurality of compressor blades in the compressor stage blades assembly as located blades , wherein each located blade has an angular position with respect to an axis of rotation of the compressor stage blades assembly ; - maintaining the located blades in their respective angular positions within the compressor stage blades assembly such that the located blades divide the compressor stage blades assembly into a plurality of sectors , wherein each sector comprises one or more movable blades and wherein the circumferential clearance is subdivided into sectoral circumferential clearances ; - circumferentially adjusting the movable blades , for each sector , such that the sectoral circumferential clearance within the sector is moved circumferentially downstream relative to the movable blades and with respect to a direction of rotation of the compressor stage blades assembly when the compressor stage blades assembly is rotated; - introducing one or more inserts in each of the sectoral circumferential clearances to maintain relative positions of the sectoral circumferential clearance and the movable blades within each sector ; and characterized by - rotating the rotor up to 20% of a maximum rotational speed of the rotor, - determining a measure of unbalance for the rotor with the compressor stage blades assembly in low-speed balancing conditions; - balancing the compressor stage blades assembly ; and - removing the one or more inserts after low-speed balancing has been completed. <EOS>