Toronto, Canada, May 10, 2011 — Constellation Software Inc. (“Constellation”) (TSX:CSU) announced today that it has been advised that four of its officers have cancelled their existing automatic share disposition plans, which were established in accordance with applicable securities laws on December 17, 2010. The plans allowed for the disposition of Constellation common shares in a systematic manner based upon pre-determined criteria. Details regarding the plans cancelled by the officers and directors are contained in the table below: