Environmental utility infrastructure company Pennon Group has confirmed group chairman Ken Harvey will retire on 31 July.Harvey, who has been in his current role since March 1997, will be replaced by Sir John Parker, who will join the board as an independent non-executive director and as deputy chairman from 1 April.Parker, who is currently chairman of Anglo American Plc, deputy chairman of DP World and a non-executive director of the Airbus Group and Carnival Corporation, has recently stepped down after three years as the President of the Royal Academy of Engineering."It is appropriate for me to retire at this time when both of Pennon's subsidiary businesses are well positioned for strong future growth," said Harvey.Pennon shares were up 1.45% to 839.50p at 08:14 on Friday.