Hong Kong will issue a set of six stamps to celebrate the 60th anniversary of the founding of the People's Republic of China next year. Hongkong Post said the designs of the stamps had not been finalised but the issue would include a sheetlet featuring Victoria Harbour and Tiananmen Square to emphasise the ties between Hong Kong and the mainland. The postal service said it hoped such a design would attract mainland customers because local demand has been sliding in recent years. Sales of special stamps peaked at HK$1.3 billion in 1997, it said, but the figure dropped to roughly HK$100 million last year, with fewer people using traditional mail and competition from other collectibles. Although philatelic products accounted for a small amount of the postal service's revenue, Vivien Lee Suk-fong, general manager of its stamps and philately division, said it needed to diversify its products to shore up revenue from the traditionally popular business. 'We have an ageing [group of philatelists],' she said. The postal service has conducted publicity programmes in primary and secondary schools and promoted setting up of stamp-collecting clubs. It also has linked with distribution agents in major mainland cities to expand its market. The 2009 collection, consisting of 11 stamp sets, will also include a Year of the Ox stamp set to be released on January 17 and a soccer-themed set, a joint issue with the Brazilian government, in November next year. With the Hong Kong 2009 Stamp Exhibition to be held in May, the postal service will have an issue that will use 'special effects' in the hope of appealing to new and old customers. 'Customers are keener on purchasing stamps that have special effects,' Ms Lee said, adding that details would be revealed later.