SWIRE Properties is continuing its mission to turn Quarry Bay into a sophisticated business district. The developers have already invested considerably in the area, with buildings such as Warwick House, Mount Parker House, Cityplaza, Cornwall House, Somerset House and Devon House, changing the area beyond recognition. Simon Haynes of First Pacific Davies explains the developer's local ambitions. ''Swire's investment has led to a natural gentrification of the area. ''Whereas before, local business consisted mainly of motor mechanic firms, as a result of the Swire buildings, it now houses some of the most prestigious companies in the world.'' With the current addition of Dorset House, in terms of office space, Quarry Bay now competed with Central as Hong Kong's premier business site, Mr Haynes said. When Dorset House is occupied by the end of December 1994, the Swire buildings in the area will accommodate up to 50,000 people, working in finance, law and advertising. Mr Haynes credits the popularity of areas such as Quarry Bay to a decentralising trend among expanding companies. ''Larger, multinational companies are now analysing the need to stay in Central,'' he said. ''With the success of the city transport and with many neighbouring regions upgrading their images, it makes sense to move a proportion of their businesses to other areas, thus saving up to HK$30 per square foot on rent levels.'' Considered Swire's local ''jewel in the crown'', Dorset House at Taikoo Place is located at the hub of a comprehensive transportation network, with easy access to the Island Eastern Corridor and the Eastern Harbour Crossing. Office workers will benefit from easy access to Quarry Bay MTR station through a system of air-conditioned walkways as well as close proximity to all types of shopping and leisure activities, plus an in-house executive dining club and health spa. The building, which has been developed on the site of Swire's 19th century Taikoo sugar refinery, forms part of a 39-storey twin-tower development. Tower II has already been committed to Hongkong Telecom, while the remaining tower is still seeking tenants. According to the leasing agents, ideal clients are prestigious firms seeking longer term leases. Swire's pragmatic business view and laissez-faire tenant selection process means occupancy requirements will be progressive. Mr Haynes believes the current surge of interest in the building proves that next year will see a dearth of space of the same calibre. ''There is a definite pattern in fluctuations in the commercial property market in Hong Kong, and, whereas a few years ago, there were several buildings available, this cycle is now ending and there will be very few grade A developments on the market after Dorset House,'' he said. ''Furthermore, Swire's offers locked rents, which is good news considering that rent levels have risen by 25 per cent this year alone.''