HONG KONG -- Shares in China's internet conglomerate Tencent Holdings rose to an all-time trading high of 298.80 Hong Kong dollars on Wednesday, following reports that Beijing has been partially blocking the popular messaging service WhatsApp from Monday.

The news sparked expectations that tighter censorship by Beijing could push users of Facebook's WhatsApp to switch to Tencent's WeChat.

Tencent shares closed 3.9% higher at HK$298.0 on Wednesday, on trading volume higher than for the other companies listed on the Hong Kong exchange.

The apparent WhatsApp blockage came after the death on July 13 of Nobel Peace Prize laureate Liu Xiaobo, who had experienced years of imprisonment in China. The move spurred concerns that Beijing was seeking to block any commemorations of Liu.

"Our findings document a significant shift in censorship after Liu Xiaobo's death," said Citizen Lab, a monitoring project at the University of Toronto on Sunday. According to research by Citizen Lab, not only the keyword "Liu," but even photos related to him were being deleted from private messages, group chats and WeChat just moments after his death.

The partial blockage of WhatsApp affects Facebook's only major product that was not already banned in China. Other major international messaging apps, including Google's Gmail and Japanese messaging app LINE have been long blocked by Beijing.

Tencent shares were also boosted by Hong Kong media reports on Wednesday that the internet giant and Fubon Financial Holding, one of Taiwan's largest financial institutions, are establishing a joint venture in Shenzhen to sell insurance. Another report suggested Tencent's cloud subsidiary had begun operations in Frankfurt.

Nikkei staff writer Mariko Tai in Hong Kong contributed to this report.