X0201 4 2003-12-15 0 0000073124 NORTHERN TRUST CORP NTRS 0001188085 PERO PERRY R 50 S LA SALLE ST CHICAGO IL 60675 0 1 0 0 Vice Chairman and CFO Common Stock 2003-12-15 4 F 0 2292 44.97 D 100775 D Common Stock 2003-12-15 4 F 0 778 44.97 D 605973 D Common Stock 15390 I ESOP Common Stock 88219 I 401(k) Total reflects distribution of 7,782 stock units as shares of common stock. Stock units (2,292) withheld in payment of taxes resulting from distribution. Mature shares delivered to Issuer by reporting person in payment of additional withholding tax due. Total reflects the distribution of net (after taxes) stock units (5,490) and the surrender of 778 mature shares in payment of additional withholding taxes. as of 9/30/2003 Represents stock units payable automatically in shares of common stock on a 1-for-1 basis. Eileen C. Ratzka POA for Perry R. Pero 2003-12-17