International service company Serco Group announced that Chairman Kevin Beeston will step down the group's AGM in May 2010.The group said it will now begin the process of appointing a new Chairman.Commenting on his decision Kevin Beeston said: 'Next year will mark my 25th anniversary with Serco and 8th year as Chairman. Over this time the group has enjoyed great success and reached many significant milestones.''With my 25th anniversary next year it seems an appropriate time to step down and for the Board to have sufficient time to appoint a successor.'