SHANGHAI: Fewer Chinese cities reported rises in home prices in September than the previous month, official data showed Thursday, as the government stood by its stance of controlling property speculation.   Prices in 31 out of 70 cities tracked by the government rose month-on-month, the National Bureau of Statistics said in a statement, down from 36 cities in August.   Prices of new homes dropped on the month in 24 cities and remained unchanged in the remaining 15 cities, it said.   "Currently the property market is generally stable," statistics bureau spokesman Sheng Laiyun told reporters at a briefing in Beijing. "The price trend of 'declining while stabilising' was extended."   China has implemented measures to control property prices for more than two years, including prohibitions on buying second homes, mandating higher minimum down-payments and imposing property taxes in some cities.   The house market had shown signs of recovery in recent months, after China slashed interest rates twice and ...