Vatican City - Pope Benedict Wednesday welcomed the Russian Orthodox Church's choice as new patriarch of a man seen as a modernizer who may usher in a thaw in difficult relations with the Vatican.
Metropolitan Kirill, 62, the acting head of the world's second-largest Church since the death last month of Patriarch Alexiy II, won 508 out of 677 valid votes cast in a secret ballot Tuesday.
The pope said he hoped Kirill would help lead the two Churches to full unity following the historic break of the eastern and western Churches in 1054.
"I assure Your Holiness of my spiritual closeness and of the Catholic Church's commitment to cooperate with the Russian Orthodox Church," he said in a message released by the Vatican.
Relations between the Russian Orthodox Church and the Vatican have been strained since the 1991 break-up of the Soviet Union, mostly over accusations that the Catholic Church used its new-found freedom to convert believers. The Vatican denies this.
The tensions prevented Pope John Paul, who died in 2005, from fulfilling his great wish to go to Moscow or meet the hardline Alexiy to further the quest for Christian unity.
The election of Kirill can make such a trip or meeting more likely, diplomats and Church sources have said.
The Vatican's Christian Unity office said in a statement it was happy about Kirill's election because he had been the Russian Church's interlocutor with them for years.
It said both sides could not lose sight of difficulties that remain in relations but pledged its full cooperation.
In his acceptance speech Tuesday night, Kirill hit out at Protestant and Roman Catholic missionaries, saying they sought converts in post-Soviet Russia. But some observers saw this as a way to placate the hard-liners in the Church.
Kirill favors closer ties with the Vatican and observers say he would lead the Church on a more independent course from the government than his predecessor.
"Kirill is probably more sympathetic to improving relations with the Vatican," said Professor John Anderson, an expert on Russian Orthodoxy at the University of St. Andrews in Scotland.
"He also has to watch what he says" considering how conservative the rest of the church is, he added.