By Mark O'Neill

BEIJING, Dec 8 (Reuter) - China enthroned a new six-year-old Panchen Lama on Friday, pressing Tibetan Buddhists to accept its controversial choice for Tibet's second-ranking monk over one named by the exiled god-king, the Dalai Lama.

A grand ceremony in the Tashilunpo lamasery in Tibet's Shigatse city enthroned young Gyaincain Norbu as the "soul boy" recipient of the spirit of the 10th Panchen Lama, who died in 1989, the official Xinhua news agency said.

China's action posed Tibetans with a stark choice between two Panchen Lamas: Beijing's boy and Gedhun Choekyi Nyima, a six-year-old na

Exiled Tibetan and human rights groups have expressed concern over the fate of Gedhun Choekyi Nyima, who is reported to have been removed from Tibet with his parents. China has denied detaining the family or violating their rights.

Signalling the importance China's atheist government places on the succession, State Councillor Li Tieying was flown to Tibet to represent the State Council, the communist cabinet.

Beijing's political message was spelt out in Li's comments to the boy in a meeting on Wednesday.

Xinhua said Li urged him to be patriotic and contribute to the unification of the motherland, unity of all ethnic groups and prosperity and progress in Tibet -- language familiar to Tibetans as warnings against the region's secession.

Ever since Beijing engineered its Panchen Lama choice on November 29, it has portrayed spiritual succession as part of an epic 30-year struggle with the Dalai Lama, who China condemns as a pro-independence "splittist."

The Dalai Lama and thousands of followers fled to India in 1959 after an abortive anti-Chinese uprising, but he continues to command the loyalty of many Buddhists in Tibet.

A torrent of state propaganda has said Gyaincain Norbu was welcomed by Tibetans and branded the Dalai Lama's selection illegal and void because it was not approved by Beijing.

China maintains it has the final say over senior lamas under a 1792 agreement with the imperial Qing dynasty. Tibetan exiles dispute this, saying the pact was informal and set not with China but with occupying Manchus who were toppled in 1911.

Beijing has even portrayed the Dalai Lama's soul boy as a sinner who had drowned a dog, describing the alleged killing as a "heinous crime in the eyes of Buddha."

Xinhua said Li Tieying was welcomed in Shigatse by 40,000 Buddhists and lay Tibetans who lined the streets waving fresh flowers and shouting greetings.

The Dalai Lama has painted a different picture, saying posters were appearing in Lhasa and Shigatse denouncing China's imposition of a rival Panchen Lama on the Tibetan people.

Residents of Tibet's three main cities were defying curfews and demonstrating against Beijing's choice, he said.

There was no independent corroboration of events in Tibet, where western reporters are rarely allowed. Foreign media were not permitted to cover the controversial Buddhist succession.

The Dalai Lama said both parents of the newly enthroned boy are local officials and Chinese Communist Party members -- who are explicitly forbidden to harbour religious beliefs.

Speaking privately, one Chinese official in Beijing said the government was winning its struggle against the Dalai Lama.

"Our strategy is to separate politics from religion and reduce the influence of religion," he said. "This is a long-term strategy. It is working with young Tibetans who are less interested in religion than their parents.

He said the Dalai Lama's exiled supporters were losing touch with their culture, speaking foreign languages but little or no Tibetan, and could never endure Tibet's harsh conditions.

"Once this Dalai Lama dies, the struggle will be over," the official said.