The Intermediate People's Court in Hangzhou imposed the sentences for "subverting state power", according to a statement by the Information Centre of Human Rights and Democratic Movement in China.

The court found the four guilty of editing a pro-democracy magazine called Opposition Party, and using the internet and e-mail to promote their message in China and overseas.

The activists are leading members of the banned China Democracy Party, which was established in June 1998.

Wu Yilong received the longest sentence of 11 years. Mao Qingxiang was given eight years, Zhu Yufu seven years, and Xu Guang five years, the human rights group said.

The men plan to appeal against the ruling.

Sentences "too severe"

Duncan Hewitt in Beijing: "China remains concerned at organised dissent"

The rights organisation condemned the ruling.

"We strongly urge UN Secretary-General Kofi Annan, who will visit China on November 14, to be concerned about the regression of China's human rights situation," it said.

The wife of one of the four said she thought the sentences were too severe.

"The government can call it an illegal organisation, but calling it subversion is too harsh," Hu Xiaoling told the news agency AFP.

The four were detained around 4 June, the 10th anniversary of the bloody crackdown on the student-led democracy movement in and around Beijing's Tiananmen Square in 1989. Their trial was held on 25 October.

CDP leader Xu Wenli is serving 13 years

Zhu Yufu and Mao Qingxiang are veteran democracy activists who were involved in the 1979 Democracy Wall movement, which pressed for a quicker pace of democracy in China.

Since last December, 18 of their CDP colleagues have been charged with subversion, most recently party leaders Liu Xianbin and Xu Wenli who were each sentenced to 13 years.