Sir John Egan will retire as chairman of Severn Trent and Severn Trent Water following the AGM on 20 July after five-years in the job.The former boss of Jaguar and BAA joined the board as a non-executive director in October 2004 and took on the chairman's role at the start of 2005.Andrew Duff, non-executive chairman of RWE npower and the German utility's former boss, will take over when Sir John leaves."We believe Andy has the relevant experience to make him the right chairman to lead the group through the next phase of our development, building on the firm foundations put in place by Sir John," said Richard Davey, senior independent director.