Informa's Chief Executive Officer (CEO) Peter Rigby is stepping down at the end of this year, the British business media group said on Wednesday.He will be replaced by Stephen Carter, currently a non-executive board director, on January 1st.Rigby has been CEO of the company since 1988 and first joined the group in 1983.Under his leadership, Informa has grown from a company valued at a few million pounds to a business with a market capitalisation exceeding £3.0bn."Like all good things, my time at Informa must come to an end. I decided many years ago that I would not overstay my welcome and leaving at the top, under my own terms and with Informa in great shape fulfils that promise to myself," Rigby said."Informa has been a major part of my life for the past 30 years, during which time the company has grown and evolved more than I could ever have imagined at the outset.I have enjoyed every minute of it and feel privileged to have been given the opportunity to manage the business over such a long and significant period."Carter was formerly President and Managing Director of Global Managed Services at Alcatel-Lucent, the telecommunications and technology group. Before joining Alcatel-Lucent, he worked in a number of senior roles in the media and communications sector, including serving a term as the Founding Chief Executive of Ofcom, the UK Communications Industry Regulator.RD