A share listing plan by a company that uses bear bile in its tonic products has angered animal right groups and celebrities in China.

Animal activists and celebrities used the internet to vent their anger at the move, which they say grants respectability to cruel treatment of captive animals.

The extraction of the bile has been condemned by animal rights groups around the world as cruel and unnecessary. The bears are kept in tiny cages and their livers and gall bladders are drained of bile twice a day through tubes inserted in their abdomens.

One species of bear used in the process, the black bear, is on the World Conservation Union's list of animals facing extinction.

The Beijing Loving Animals Foundation delivered a letter to the China Securities Regulatory Commission, urging it to withhold approval of the initial public offering by Fujian Guizhentang Pharmaceutical Co.

More than 70 Chinese celebrities signed the letter, including famed writer Bi Shumin, popular singer Han Hong, snooker player Ding Junhui and Li Dongsheng, president of the Chinese consumer electronics giant TCL, the website whatsonxiamen.com reported.

The social network Weibo, the Chinese equivalent of Twitter, was inundated with comments blasting the company for its use of bear bile.

Animal rights are gaining increasing attention in China, where animal parts are still used in some traditional medicines.