Upmarket London property developer Capital & Counties Properties said progress in regenerating iconic London sites had helped it boost its total portfolio value by a fifth.Capco said the value of its Covent Garden Market and properties on surrounding streets had risen 19% to just under £1.2bn in the 12 months to December 31st.During the year, the group signed 12 new retailers and restaurants for Covent Garden including Dior Beauty, Burberry Beauty Box and Shake Shack.Capco, which also owns the Earls Court and Olympia exhibition centres and related properties in west London, said the Earls Court interests rose a quarter in value to £934m as it gained planning consent for a plan to redevelop the area.The group's net asset value increased 22% to 249p per share and its total property value rose 20% to £2.3bn.It proposed a final dividend of 1p per share, giving a full-year dividend of 1.5p per share.Chairman Ian Durant said: "This was another year of significant performance for Capco. Our focus on London and our strong financial position will enable us to build on the momentum and continue to deliver market-leading total returns for our shareholders from both our landmark estates."Shares in Capco rose 3.7p or 1% to 385p in early trading in London.PW