CHENGDU, June 29 (Xinhua) -- China is to send two giant pandas to Spain for research, Chinese authorities announced on Friday.

A seven-year-old male "Bing Xing" weighing 140 kg and a four-year-old female "Hua Zui Ba" weighing 93 kg would be sent to the Madrid zoo, said Zhang Zhihe, head of the Giant Panda Breeding and Research Base in Chengdu, southwest China's Sichuan Province.

The international cooperation program between China and Spain on the protection of endangered pandas was launched on Friday at the Chengdu base.

The Spanish zoo raised the program with the Chengdu base in 2005, Zhang said, but the base was still waiting for approval to send the pandas abroad.

Zhang did not reveal how long the program will last nor when the pandas would return.

The launch was on the agenda of the six-day state visit to China by Spanish King Juan Carlos I who left the country on Friday.

Giant pandas are among the world's most endangered species. State Forestry Administration figures show 1,590 pandas live in the wild, mostly in the mountains of Sichuan and more than 210 pandas live in captivity.