BRITISH computer software company Madge Networks has opened an international office in Hong Kong which aims to increase its profile in developing markets. The company claims to be the world's second-biggest seller behind IBM of networking products and technology, which allow users to build more efficient networks. The Hong Kong office, to be called Madge International, will serve as headquarters for the company's sales and support services in Asia, the Middle East, Oceania and Africa. The company also has European, US and Japanese offices. Director of finance Tim Luscombe said in Hong Kong, the group would target the financial sector, which was a strong market area for the company. Users of Madge products include Dah Sing Bank, Bank of Commerce, and oil companies Caltex and Mobil. Vice-president of international sales Julian Brookes said: ''Hong Kong lies at the centre of our international operations and the decision to base our new headquarters here is a clear indication of our confidence that Hong Kong's role as a regional centre will grow in importance.'' Founder and chairman Robert Madge said the seven-year-old firm's market share was growing, while IBM's was shrinking. ''IBM has lost its ambition, and we have not,'' he said.