PARIS (Reuters) - Dutch bishops visiting Rome this week have given Pope Francis a dramatic snapshot of the steep decline of Roman Catholicism in its European heartland.

Both Catholic and Protestant Christian ranks have shrunk dramatically across Europe in recent decades, and hundreds of churches have been sold off to be turned into apartments, shops, bars or warehouses.

In the Netherlands, churches have been closing at a rate of one or two a week. The bishops told the pope in Rome on Monday that about two-thirds of all Roman Catholic churches in the Netherlands would have to be shut or sold by 2025, and many parishes merged, because congregations and finances were "in a long-term shrinking process".

Their five-yearly report blamed a "drastic secularisation" of society, although a critical group of Dutch lay Catholics said the scandal of sexual abuse of minors by priests, which has afflicted many Catholic dioceses around the world, had also driven many people away, as had the closures themselves.

The only bright spot for the Dutch church was the finding that the election of the popular Pope Francis in March appeared to have slowed the exodus this year.

Francis has made it his mission to restore the Church's relevance with a message of simplicity and charity, although his parallel plan to open up its hidebound institutions may take years to make itself felt.

ABUSE SCANDAL

Cardinal Willem Eijk, head of the Dutch bishops' conference, said that the bishops' 90-minute meeting with the pope had examined the Dutch Church's decline and the effects of the scandals that first came to light in 2010.

Tens of thousands of children were abused by priests over decades, according to an independent inquiry, and the Church has apologised and begun paying large sums in damages.

More than 23,000 Catholics quit the Dutch Church in 2010, the peak of an exodus in which an average 18,000 have left each year since 2006. This year, however, only about 7,500 had left by October.

Catholicism is still the Netherlands' largest faith, officially claiming 24 percent of the 16 million population. Next come the Protestant churches at 18 percent and Islam at 5 percent.

But Eijk told Vatican Radio that government estimates put the Catholic total at 16 percent, falling to 10 percent by 2020. And the bishops' report said a mere 5.6 percent of those declared as Catholics actually went to church regularly.

Ad de Groot, a lay Catholic leader in Eijk's archdiocese of Utrecht, said secularisation and the sexual abuse crisis had prompted people to leave in the past. But now, the very plan to close churches is alienating the Catholics who are left, he said.

De Groot's group accuses the bishops of merging parishes without consulting those who are losing their local churches. "Many people are angry and disappointed," he said.

His group told the Vatican last week that half of practising Catholics would drift away in coming years as their churches closed.

(Editing by Kevin Liffey)