A private-sector data provider has quietly stopped publishing a widely watched barometer of China’s property market that was one of the few alternatives to an official gauge. Beijing-based Fang Holdings, China’s largest online real-estate portal, has since at least 2010 published its compilation of home prices in 100 Chinese cities into a monthly index. The index usually shows sharper increases in China’s runaway property prices than the official index. Fang has decided to stop updating the index online, to avoid disrupting the property market, Vincent Mo, Fang’s chairman and chief executive, told The Wall Street Journal. In November, the last month for which Fang’s data was available, showed prices across 100 cities up 18.7% on the year. But official data showed the first 11 months of the year rose 10.8% compared with a year earlier.