The churches have been separated for 1,000 years

However, Mr Putin said he did not expect the Pope to visit Russia soon.

"I see my objective not in helping to get the pope to Russia but in helping steps towards unity. And naturally this is possible only if there is an understanding between churches," he said.

The Russian leader is due to attend an EU-Russia summit on Thursday.

Missionary row

The BBC's David Willey in Rome says relations between the Russian Orthodox and Roman Catholic Churches are tense, because the Russian authorities have expelled some Catholic priests and refused re-entry visas to others.

He says Mr Putin is unlikely to renew an invitation extended to the Pope by Boris Yeltsin and Mikhail Gorbachev because of opposition by the head of the Orthodox Church in Moscow.

The Russian Patriarch, Alexei, accuses the Pope of seeking converts inside Russia and has steadfastly refused to meet the Pope unless the Vatican changes its missionary policies, which is very unlikely.

Earlier, Mr Putin met President Carlo Azeglio Ciampi, who praised him for promoting economic reform in Russia.

Italy is Russia's second-biggest trading partner after Germany, and Mr Putin has developed a close personal friendship with Mr Berlusconi.

The Russian leader has already visited Italy this year, spending three days at Mr Berlusconi's villa on the island of Sardinia.