ACTIVITY in the mainland property market has slowed down in the past few months, but a real estate consultant says the prospects remain optimistic. Michael Choi Ngai-min, managing director of Land Power Property Consultants, said yesterday transactions had decreased by 20 to 30 per cent in China in the past quarter due to Beijing's tight credit policy. But property prices in major cities had managed to remain stable except for those projects that were badly located, he said. In view of the tight credit policy, Mr Choi expected small developers would face difficulties in getting funding for their projects. ''Accordingly, some mainland property development projects are expected to be shelved or delayed, which will lead to a reduction in supply,'' he said. He said only major developers could survive in the current unfavourable circumstances. Mr Choi also said the yuan's instability would be a concern for Hong Kong investors wanting to buy property in China. If the yuan continued to depreciate, China could face further inflationary pressure which would fuel the rise of property prices, he said. Mr Choi said Hong Kong people should be ''highly selective'' in buying properties in China where location was essential for the potential of growth in prices. He predicted that properties in coastal cities, especially Guangzhou and Shenzhen, would continue to receive good support.