Guo Guangchang, chairman of Fosun International. [Photo/IC]

It was a tough day on Friday for all of the companies related to Fosun International, whose chairman, Guo Guangchang, known as the Warren Buffett of China, was confirmed to "have lost contact".

Later on Friday, Fosun International announced that "Guo is assisting judicial authorities in an investigation, and he is still able to take part in the company's decision-making process in an appropriate way". Guo made his last public appearance on Nov 26.

Two Hong Kong-listed companies, Shanghai Fosun Pharmaceutical (Group) Co and Fosun International, announced earlier on Friday morning that trading of their shares would be halted due to "pending release of an announcement containing further information about the company".

Five other companies listed on the Chinese mainland in which Fosun International directly holds a majority stake also suspended trading. They include Shanghai Yuyuan Tourist Mart Co, Nanjing Iron and Steel Co and Hainan Mining Co.

Public information shows that 21 companies listed on the mainland have Fosun International among the top 10 shareholders. Many of them saw their share prices dive on Friday, with medical equipment company Dirui Industrial Co being the biggest loser, with a 6.53 percent slump.

Before Friday, the market value of the 21 companies combined was as much as 306.8 billion yuan ($47.5 billion), with their total sales revenue in the first three quarters reaching 115.6 billion yuan.

Earlier media reports showed that Fosun International has been involved in a corruption case involving Wang Zongnan, former general manager of Shanghai Friendship Group and Lianhua Supermarket. Wang, convicted of taking bribes and embezzling public funds, was sentenced to 18 years in prison in August.

Legal documents provided by Shanghai No 2 Intermediate People's Court showed that there was an illegal transfer of interests from Wang to Fosun International after a joint venture was established between Shanghai Friendship and Fosun International.

Cyrus Ng, an analyst with China Galaxy Securities Hong Kong, said that Guo's being out of reach will definitely have a huge impact on the companies in which Fosun has invested.

Founded with a registration capital of only 38,000 yuan as a technology consulting firm in 1992, Fosun International has grown into a conglomerate with investments both at home and abroad led by Guo, who often has described himself as "a disciple of Warren Buffett".

The company has accelerated its overseas expansion in recent years.

Yuyuan Tourist Mart Co Ltd, in which Fosun International holds a 29.9 percent stake, acquired in November a 100 percent stake of Hoshino Resorts Group's ski destination Resort Tomamu, in Japan's northernmost island Hokkaido, for 18.36 billion Japanese yen ($151.3 million).

Insurance has been a major focus of its overseas investment lately.

In May, Fosun International bought an 80 percent stake of US insurer Ironshore Inc. The company's interest in insurance business was manifested by a 1 billion euro ($1.1 billion) acquisition of the insurance arm of Portuguese state bank Caixa Geral de Depositos SA at the beginning of the year.

It also marched into entertainment and tourism industries, by acquiring French holiday group Club Mediterranee in March and purchasing a 25 percent stake in Cirque du Soleil in May.

Guo ranked 17th on the 2015 Hurun Rich List with a personal wealth of 50 billion yuan, an increase of 79 percent year-on-year.

Rupert Hoogewerf, founder and chief researcher of the Hurun Rich List, considered 48-year-old Guo one of the most important Chinese entrepreneurs in recent years, largely due to his overseas reach.