Shares of China's three leading property information providers plunged in the US on Friday, underscoring the increasingly harsh business environment amid a weakening property market.

Soufun Holdings Ltd, China's biggest real-estate information website, sank 17 percent on the New York Stock Exchange, the most since 2011. E-House China Holdings Ltd, a Shanghai-based property brokerage, dropped 5 percent. Leju Holdings Ltd, an online brokerage, sank 6.4 percent.

Soufun's retreat comes after the Beijing -based company announced a 40 percent discount on the fees that it charges agencies for listing property information. According to analysts, the discount and other promotions will cost Soufun up to 500 million yuan ($80.53 million). The discount came after nine real-estate brokerages in the city of Hangzhou, which account for around 80 percent of the local brokerage market, stopped putting information on Soufun last month, in a bid to get Soufun to reduce the rates.

China's property market has been losing steam for most of this year. The National Bureau of Statistics said on Friday that property sales dropped 8.5 percent in the first five months of the year from the same period last year. During the period under review, home sales declined by 10.2 percent, it said.

Investment in property construction kept growing in the first five months of the year, but growth is decelerating. According to the NBS, 3.07 trillion yuan was invested in the first five months, up 14.7 percent year-on-year. However, the rate is 1.7 percentage points lower than the 16.4 percent growth in the January-April period.

Against this backdrop, many home buyers are taking a wait-and-see approach after years of price increases. That is hurting the business for companies such as Soufun, whose profits mainly come from brokerages, analysts said.

Deutsche Bank AG analysts led by Vivian Hao told Bloomberg on Friday that they have cut their rating on SouFun from 'buy', saying in an e-mailed research note that there is a "fair chance" the company will lower its 2014 earnings guidance.

Tian X. Hou, founder and CEO of Chinese equity research firm T.H. Capital, wrote in an article on chinamoneynetwork.com on Wednesday that she is positive that Soufun can make it through the hard patch.

"As a leading real estate service platform, we believe Soufun's diversified services are likely to offset market fluctuations. As such, we are adjusting our revenue growth outlook for each service line and maintain our 'buy' rating," Hou said.

She believes that the headwinds may force developers and agencies to promote their inventories more proactively than in a normal market situation in order to survive and Soufun is well-positioned to benefit from such promotions.

The management of Soufun had recently indicated that it was bolstering its efforts by hiring more sales personnel. Its sales force increased to 4,500 people by the end of May, compared with 3,500 by the end of the first quarter.