Zuo Hui, the founder and chairman of KE Holdings, a China-based real estate services provider, passed away on Thursday due to "an unexpected worsening of illness", said the company without elaborating.

"From Lianjia to Beike, it's extremely fortunate for us to work hard with Zuo Hui and promote the progress of the industry together. We have lost a close partner and a wise teacher," the company said in a statement on its official We Chat account.

In 2001, Zuo founded Beijing Homelink Real Estate, also known as Beijing Lianjia, and started Ziroom in 2011 to offer long-term apartment rentals.

He then consolidated Beijing Lianjia with other agencies, including Century 21 China Real Estate and Zhonghuan Real Estate, to form KE Holdings in 2018, which is better known as Beike Zhaofang.

Last August, the leading integrated online and offline platform for housing transactions and services made its U.S. debut, with Tencent, Softbank, Hillhouse Capital, and Sequoia China Capital as its major investors, becoming the largest IPO of a Chinese company since March 2018 at the time.

The company earlier in the day announced a total of 20.7 billion yuan (about $3.2 billion) revenue for the first quarter, a year-on-year increase of 190.7 percent. And its net profit was over 1 billion, compared with a net loss of 1.2 billion in the same period last year, with 48,717 stores and 528,424 agents as of March 31.

The firm's U.S. shares plunged more than 10 percent in pre-opening trade on the news, which closed at $50.26 last night, with a total market value of $59.855 billion.

The company said it will "make appropriate arrangements for corporate governance and related matters and make an announcement in due course within two weeks".

Data from the National Bureau of Statistics showed that in terms of value, China's commercial housing sales rose 8.7 percent year on year in 2020 to 17.36 trillion yuan last year, up 2.2 percentage points from 2019, and the country's investment in property development rose 7 percent.

Last November, China's market regulator issued draft anti-monopoly rules relating to the country's online economy to enhance oversight of the online service tycoons.

Peng Yongdong, CEO of KE Holdings then responded that the draft is aimed at large internet companies with huge market share while KE Holdings has just been established for more than two years. "The housing transaction market where KE dabbles in has reached 32 trillion to 35 trillion yuan, but the market share of KE in 2018 was only 5.3 percent, 9.1 percent in 2019, and probably 12 percent to 13 percent in 2020.

Data from Lianjia showed that in 2019, the proportion of online business in its entire business increased to 42.3 percent, among which the online transaction business accounted for the highest proportion, at 50.9 percent.

Meanwhile, KE was among 34 of the country's largest online service providers, including Alibaba, Tencent and ByteDance told by China's top authorities for regulation of markets, cyberspace and taxation in April to hold self-inspections to rule out any abuse of their market dominance.