Centaline's Centa-Salesman Index fell to 44 from its highest 80 in June. The property agency says if the index falls below 45 it indicates a downtrend in home prices.
The property market is seeing a price-cut trend, owners are not optimistic and some are offering price cuts of up to 13 percent.
The index showing property agents' views has fallen after struggling for weeks, signalling the market is in a downturn.
Johnny Sin, Centaline Property manager, said that a two-bedroom unit at Island Resort in Siu Sai Wan was priced at HK$8.30 million and sold for 13 percent less at HK$7.22 million. A two-bedroom home at Island Resort sold for HK$8.88 million in July.
A low-level apartment at Kingswood Villas in Tin Shui Wai was sold 10 percent lower than its asking price at HK$4.62 million, Super Chan, manager of Ricacorp Properties, said.
And a car parking space at Kingswood Villas slid to HK$1.48 million in April.
Willy Liu Wai-keung, chief executive of Ricacorp, said that if the government does not increase the land supply, it is hard to see a positive impact.
Sammy Po, chief executive of the residential division at Midland Realty (1200), said prices are under pressure because of the negative impact of the trade war and will not rise in the short term.
In luxury housing, Patrick Au, director at Midland Realty, said the Greater Bay Area will shore up the Hong Kong market and the number of transactions in the secondary property market over HK$50 million may reach a record high level of 174 units since 2007.