IN a solid show of confidence in Hong Kong's future, the cash-rich Chinachem group yesterday announced it would build the world's tallest building in Tsuen Wan for an investment of about $10 billion. To be named Nina Tower after its chairman, the 468-metre high office building will eclipse Malaysia's 450-metre Petronas Towers and China's 457-metre Chongqing Tower to become the highest in the world when completed in 1998. Analysts said the colossal edifice would help turn Chinachem, already a powerful player in the territory, into an even more formidable developer in post-1997 Hong Kong. Its financial prowess is demonstrated by the group's decision to go it alone, without using bank loans, to finance the 108-storey building, despite the massive investment. Shanghai-born chairman Nina Wang said: ''We have always relied on our own resources to finance our projects. The land for this building is already there, so the main cost is construction. ''We have rental income and instalment receivables to tide us through. So, at the moment, we have no plans to borrow from the bank.'' Development cost is estimated at $4 billion, with the rest taken by the cost of the land. She said Chinachem preferred to work on the project alone because ''on major projects, we have always done it alone''. ''It is simple and we can do whatever we think is right. With partners, things can get complicated.'' The decision to build Nina Tower was based on Ms Wang's optimism that Hong Kong's role as the gateway to China would create solid demand for office space in the years to come. ''Hong Kong is already an international financial centre. That role will become even more important because of China's economic development. More foreign companies going into China will set up offices in the territory, which will lead to more demand for office space.'' Ms Wang said despite the high cost of doing business in Hong Kong, many foreign companies would continue to move in because of the many advantages offered. ''It will be like Tokyo. Although everybody says it's expensive, we still see many people going to Tokyo to do business.'' Facing the Tsuen Wan waterfront, the office tower will be built on 210,000 square feet of land. Preliminary work is being carried out and construction of 2.1 million to 2.3 million square feet of office space is expected to begin next year. When completed, the building will be mainly for lease. ''Most of our office buildings are leased out. It's easier to manage buildings when they are leased,'' said Ms Wang. Although Tsuen Wan was now an industrial heartland, the astronomical office rentals in the prime office districts were forcing more companies to seek offices in cheaper areas, she said. As a result, many buildings in Tsuen Wan were gradually being converted for industrial and office use. Tsuen Wan's relative proximity to the Chek Lap Kok airport would also create sufficient demand for office space in that area. Bought last year, the land was originally slated for a residential project, but a proposed flyover in the vicinity would make it too noisy for residents so it was decided that an office building was more appropriate. Nina Tower will reserve the ground level for general public use, which will have a specially designed garden in front. Just last month, Chinachem announced that it would pay $2.2 billion to buy two prime office buildings in Central from the Wing On group. The properties are Wing On Life Building and Wing On Central Building, which have a gross floor area of about 164,528 square feet.