* Closed-door Rome event bars press, venue undisclosed

* Catholic commentators challenge Thiel's world vision

* No meetings planned with Pope Leo or PM Meloni

By Crispian Balmer

ROME, March 15 (Reuters) - Peter Thiel, the U.S.

billionaire venture capitalist and early supporter of President

Donald Trump, launched on Sunday a series of closed-door

lectures in Rome exploring the concept of the Antichrist,

drawing scrutiny from Catholic commentators.

The invitation-only conference, which runs until Wednesday,

is not open to the press and its venue has not been publicly

disclosed. Organisers quoted in the media say participants are

drawn from academia, technology and religious circles.

A co-founder of Palantir Technologies ( PLTR ), an AI software

company with deep ties to the U.S. defense and intelligence

agencies, Thiel has in recent years devoted increasing attention

to religious and philosophical ideas.

Last year he held a similar series of talks in San Francisco

exploring the possibility that the Antichrist - a figure who

opposes or denies Christ - could emerge on the global stage.

In particular, Thiel has said he is wary that an Antichrist

will emerge who will create a one-world government on the

promise of something like stopping nuclear, AI or

climate-induced disaster.

Thiel, 58, grew up in an Evangelical Christian family and

has said Christianity shapes his worldview.

His visit has caught the attention of the Roman Catholic

Church, which, under Pope Leo, the first U.S. pontiff, has

openly criticised some of Trump's right-wing policies. Leo has

also warned of the dangers posed by AI.

Catholic universities in Rome denied press speculation that

they might be hosting the event and no meeting is scheduled

between Thiel and Leo, according to the pope's official agenda.

'PROLONGED ACT OF HERESY'

Father Paolo Benanti, who advises the pope on artificial

intelligence, wrote in an essay published on Saturday that Thiel

operated as a "political theologian" within Silicon Valley.

"Thiel's entire action can... be read as a prolonged act of

heresy against the liberal consensus: a challenge to the very

foundations of civil coexistence, which he now considers

outdated," Benanti wrote on Le Grand Continent website.

The piece was headlined: "American heresy: should Peter

Thiel be burned at the stake?"

A newspaper owned by the Italian bishops' conference,

L'Avvenire, also published a series of articles this past week

that were highly critical of Thiel.

One article warned that technology leaders should not be

allowed to define their own ethical limits, arguing that

governments had to defend democratic oversight of digital

platforms and resist the spread of disinformation.

Thiel retains close ties with figures in Washington,

including Vice President JD Vance, himself a Catholic convert.

Thiel's appearance in Rome follows a string of visits to Italy

by prominent figures linked to the U.S. conservative movement,

including Steve Bannon, Elon Musk, and Vance himself.

There is no meeting scheduled between Thiel and Prime

Minister Giorgia Meloni, according to Meloni's agenda.