Moscow - Patriarch Kirill I was formally installed as new head of the Russian Orthodox Church Sunday at an elaborate ceremony in Moscow's Cathedral of Christ the Saviour attended by Prime Minister Vladimir Putin and President Dmitry Medvedev.

Metropolitan Kirill of Smolensk and Kaliningrad succeeded Patriarch Alexiy II, who died in December, to become the 16th leader of the church following his election by the Church Council last week.

Kirill, 62, is regarded as a relatively liberal leader who is well-known through television appearances, and observers say he will be looked to by millions to help the Orthodox Church play a greater role in Russian life increasingly beset by economic hardship.

The formal enthronement came after senior bishops chanted "Axios!" - the Greek word for "worthy" - three times.

Kirill's appointment has been welcomed by Putin and also in Rome by Pope Benedict XVI, who has met Kirill several times - a factor, observers say, which could help a warming of ties between the two churches.

Kirill's appointment comes at the peak of the Orthodox Church's popularity.

Alexei II presided over the sweeping revival of the church in the nearly two decades since the collapse of the Soviet Union. However, he was criticized by some for allowing the church to fall too much under the Kremlin's sway.

As the church's top diplomat, Kirill filled the same post held by Alexei II before he became patriarch in 1990, and he is widely recognized as the public face of the church.

The church external relations department enjoyed relative autonomy in Soviet times, but many senior clergy in the branch have since been accused of collaborating with the KGB.

Many hope Kirill's liberal stance will allow for a rapprochement with the Vatican, which split with the Orthodox Church almost 1,000 years ago.

In December 2007, Kirill held a sensitive meeting with Pope Benedict XVI in Rome and voiced optimism that relations may improve.

Experts say Kirill has worked hard in the past month to win the support of more conservative strains of the church and change perceptions that he is more of a politician than a spiritual leader. dpa