BEIJING (Reuters) — Pope Benedict’s planned letter to China’s Catholics will urge healing between both sides of the divided church and set out the Vatican’s hopes for expanded religious freedom in the Communist country, a church source said.The letter, due to appear within weeks, will mark a major step in the Holy See’s effort to open formal ties with China, severed after the Communists came to power in 1949.

But the Pope would focus on urging unity among believers now split between China’s state-backed church and an “underground” one loyal to Rome, said the source familiar with dealings between the Vatican and Beijing.

“His primary concern is to help the reconciliation between the two communities,” said the Hong Kong-based church representative, speaking by phone overnight. He requested anonymity, citing the sensitivity of ties.

“I think there will be a strong invitation to the two sides to try to work together to heal those differences.”

Pope Benedict would send a copy of his letter to China’s foreign ministry days before its public release.

Beijing and the Vatican have been divided since the Chinese Communist Party came to power. The party first persecuted the faithful and then in the past three decades allowed worship in state-controlled churches, mosques and temples.

In recent years, the two sides have edged towards reviving formal ties, and a Vatican meeting in January focused on the issue. Since his election in April 2005, Pope Benedict has made normalising relations one of his priorities.

But the Pope’s planned letter highlights how the future of the Chinese church rests not just on high-level negotiations but on relations among millions of believers who share basic beliefs but have been split by politics.

China’s 10 million or more Catholics are divided between the government-approved church, which honours the Pope but accepts controls demanded by the Communist Party, and the underground church which recognises only Vatican authority.

In recent years the divide has created tensions over the appointment of bishops, with Chinese authorities sometimes naming bishops who have not won the blessing of the Vatican, something even clergy in the state-backed church now often seek and get.