HANOI is a city torn - between the need to develop and the desire to keep its heritage in one piece. As a result of strong foreign support for preservation, the city will avoid the fate of her neighbours and maintain much of her former glory in the face of economic growth. The Friends of Hanoi Architectural Heritage Foundation, set up last year, has brought government departments together on issues of conservation, in an effort to reverse their reputation for not co-operating with each other. At the foundation's first international symposium last month, Communist Party officials met international experts in architecture and town planning to identify the critical issues facing Vietnam's capital. John Goodyear, the director of Friends of Hanoi, said: ''It's hard for the Vietnamese to realise that they are sitting on a gem. They are hungry for economic development and they associate that with high-rise buildings. ''But I think we reached a common chord and there was definitely a strong message from the experts to the Vietnamese not to underestimate the value of their country and the particular beauty of their capital. ''They were told that there are two sorts of investors: those who will come in and rape you and leave and those who will do something sympathetic and stay.'' The aim of Friends of Hanoi was to avoid ''a disaster of epic proportions just waiting to happen'', Mr Goodyear said. Many people see Hanoi as one of Asia's most beautiful and fascinating cities. Its charm lies in its wide, tree-lined boulevards, grandiose public buildings and colonial villas, built by French city planners between 1886 and 1954. They transported the ambience of Paris to the heart of Southeast Asia; the magnificent opera house is still regarded as the region's grandest. Hanoi's architectural splendour is enhanced because there are only a few vehicles. Bicycles, ''cyclos'' (rickshaws) and mopeds are the main form of transport. The fear is that a Manhattan-style skyline will appear among the villas, 670 of which are unoccupied and gently deteriorating. Some sympathetic restoration projects are already complete. The Australia-New Zealand Bank (ANZ) has brought one old villa back to its former glory and refurbished it as an office. However, Hanoi needs more than a preservation programme; the threat to its heritage is socio-economic. Legislation governing land use and development is virtually non-existent. The city's drains, roads and electricity system cannot cope with its 3.5 million residents and will be under more pressure once investment picks up. The problem is most acute in the ancient quarter, a warren of narrow streets where traditional tradesmen, from wool sellers, metal-box makers, grocers and antiques' merchants have gathered for centuries. ''There is great unemployment . . . in the ancient quarter. Most people are happy to live four generations in one room, with the workshop below. None of the locals wants to move. Conditions are desperate,'' Mr Goodyear said. Friends of Hanoi, which is largely sponsored by companies operating in the city, has set up a management committee under the chairmanship of former Australian prime minister Gough Whitlam. The committee brings together international experts and members of Vietnam's ministries of Culture and Construction and the Hanoi's People's Committee. It has ensured a dialogue between government departments. The foundation has started its work by creating a database to help foreigners find out who to approach on investing in Hanoi. It is working on schemes to develop planning and zoning laws. Mr Goodyear said: ''There must be height restrictions and traffic controls. Until such laws are in place, there is no point trying to conserve the city.'' But Mr Goodyear tempers optimism with realism: ''I think there will be some successes and some failures. I think the ancient sector and the French quarter will survive. But it is inevitable that, by 2020, we shall see a few high-rise buildings among it all.''