BEIJING (AP) _ China's boldest advocate of democracy and human rights, Wei Jingsheng, was convicted today of trying to overthrow the government and sentenced to 14 years in prison.

Wei, 45, already has spent 16 years in detention for his pro-democracy activities. A guilty verdict was almost a foregone conclusion because most criminal trials in China result in convictions.

``This is extremely serious. This is as bad a blow to human rights as 1979,'' said Liu Qing, head of the New York-based Human Rights in China and an associate of Wei's in the brief 1978-79 pro-democracy movement in Beijing.

In the first details of the government's case against Wei, the nationally televised evening news said he bought newspaper companies, tried to set up companies to support the democratic movement and strategized with dissidents overseas to overthrow the government.

``It's all rubbish,'' said Wei's sister, Shanshan. ``The Chinese government is shameless. They operate like an organized crime group that pays no attention to the law.''

Wei was first sentenced to prison in 1979, at age 29, for agitating to overthrow the socialist system and leaking secrets on China's border war with Vietnam. He had written powerful essays warning that China's attempts at economic development would be meaningless without democracy and human rights.

After his release from prison in September 1993, Wei immediately resumed his calls for democratic freedoms. He disappeared into police custody in April 1994 and was held for 20 months without either charges or any chance to see his family. He was charged with sedition in November.

Wei was given only days to prepare a case with a lawyer's help. Although China promised an open trial, police barred foreign reporters and diplomats from the court building.

The state-run Xinhua News Agency issued a two-sentence report on Wei's conviction and sentence less than six hours after the trial began. It did not give details of the proceedings.

Photos released by Xinhua show an expressionless Wei sitting in a chair in the courtroom. Wei wore a padded army-style jacket and had a crew cut.

The television news showed no footage of the trial, but said Wei admitted to the facts presented by the court. Wei made a statement in his defense, but its content was not given.

The report said he bought newspapers and set up cultural companies as propaganda fronts and invested in 12 percent of a Beijing credit union to finance democratic activities.

Wei also asked foreigners for ``hundreds of thousands of dollars'' to fund a series of activities, the report said.

``He published articles outside China attacking the Chinese government, slandering the socialist system and the leadership of the Communist Party,'' the news announcer said.

``He exchanged signals with anti-China organizations abroad to overthrow the dictatorship of the people and split the country.''

Wei can appeal the sentence within 10 days.

``Authorities have the most difficult job. It's always difficult to restrain thinking,'' said Yang Jing, a friend of Wei's for more than 20 years who spoke with reporters outside the Beijing Intermediate Court building. Dozens of police stood nearby in heavy fog, under the city's first snowfall.

Police detained Yang and another man walking toward a subway station after they spoke with reporters, a witness said.

Wei's 1994 arrest started off a new wave of repression by the Communist Party leadership. Most of China's small number of active dissidents have been detained or harassed, or have gone into exile.

Wang Dan, a student leader in the 1989 pro-democracy demonstration, was taken into police custody in May. His fate is unknown.

The leaders are determined to stamp out dissent as they struggle to succeed Deng Xiaoping, the architect of China's economic reforms who is now too feeble to rule. They have been emboldened by Western governments' unwillingness to sacrifice growing trade with Beijing.

The U.S. Embassy had no immediate comment. A U.S. diplomat waited outside the courthouse during the trial, a spokeswoman said.

The U.S. House of Representatives passed a resolution late Tuesday demanding Wei be released or given decent treatment. Fourteen senators sent a letter to President Clinton urging a tougher condemnation of the trial.

In Hong Kong, which reverts to Chinese rule in 1997, democracy activists condemned Wei's sentence and said it sent a bad message to the colony about its own future.

``Today's Wei Jingsheng will be tomorrow's Hong Kong people,'' legislator Albert Ho said at a news conference shortly after Wei's conviction.

Protests against Wei's sentence were planned outside the Hong Kong office of the Xinhua News Agency, China's de facto embassy in the colony.