Great Portland Estates PLC 10 July 2006 Notice of Quarterly Valuation Announcement Great Portland Estates plc advises that it will announce its portfolio valuation as at 30 June 2006 on Tuesday 18 July 2006. Enquiries Great Portland Estates plc: Desna Martin 020 7647 3093 Finsbury Group: James Murgatroyd 020 7251 3801 This information is provided by RNS The company news service from the London Stock Exchange