By Philip Pullella

VATICAN CITY (Reuters) - - If the Catholic cardinals entering the conclave to elect a successor to Pope Francis are looking for a steady administrator to run the Church and bring some calm after three consecutive papacies that were at times tempestuous, they may look no further than Pietro Parolin.

On nearly every media shortlist of papal contenders, Parolin has been the Vatican's secretary of state for the last 12 years, effectively the number two position in the Church. He is also the Vatican's top diplomat.

The two roles mean Parolin - a 70-year-old from a small town in Italy's deeply Catholic northern Veneto region - is perhaps the candidate best known to the 133 cardinal electors who will enter the Sistine Chapel for the start of the secret conclave on Wednesday.

Cardinals who have visited Rome from around the world on Church business have met him and he has visited most of their countries. Two cardinals from two African countries, for example, probably know Parolin just as well or even better than they know each other.

Under Francis, who died on April 21, the number of occasions all the world's cardinals could meet altogether in Rome was limited. "We have to get to know each other" has been a common refrain to reporters from otherwise tight-lipped cardinals entering and leaving pre-conclave meetings known as "General Congregations". 

Parolin is seen as a quiet diplomat who is pragmatic more than conservative or progressive. He occasionally had to quietly put out fires caused by the late pope's remarks.

Francis, an Argentine who was the first pope from the Americas, gave media interviews and sometimes spoke off the cuff in public. 

"He (Parolin) knows how to take a punch for the number one and for the institution," said one cleric currently based abroad who has worked with him and has known him for many years, who asked not to be identified because of the secretive nature of the conclave.

One such recent occasion was when the late pope suggested last year that Israel's military campaign in Gaza might amount to genocide. Parolin agreed to meet with then-Israeli ambassador to the Vatican, Raphael Schutz, who told him that Israel wanted the pope to say more about Israel's right to defend itself.

When Francis said Ukraine should have the "courage of the white flag" to end the war there, the comment drew widespread criticism from allies of Kyiv but was hailed by Russia. Parolin quietly told diplomats that the pope meant negotiations, not surrender.

CAREER FOCUSED ON DIPLOMACY

Parolin entered the minor seminary when he was 14 and was ordained in 1980. He has spent nearly all of his career in Vatican diplomacy, in Rome and around the world. He has never headed a Catholic diocese, which would have given him more pastoral experience.

But those who know him say this is not a deficit because in running an organization as complex as the Vatican's central administration and representing the pope around the world, he has had many contacts with many members of the faithful.

"He traveled to many places and dealt with all categories of people in diverse regional, cultural and linguistic environments. He knows the universal Church," the overseas cleric said.

Some conservative-leaning cardinals in the U.S. and Asia have expressed disagreement with Parolin because he is the main architect of a secret 2018 Vatican agreement with China.

They call the deal, which gives Chinese authorities some say in who will serve as Catholic bishops, a sell-out to the Communist Party. Supporters say it is better than no dialogue at all between the Church and China and that even Pope Benedict, known as more conservative than Francis, favored it. 

Another criticism is that under Parolin's watch the Secretariat of State lost some $140 million in a botched investment in a London property. 

The deal led to a Vatican corruption trial in which Cardinal Angelo Becciu, who was one of Parolin's top deputies, was convicted of embezzlement and fraud. 

Parolin testified at the trial but was not among those accused. Becciu denies wrongdoing and is appealing the verdict.

Parolin's personality is definitely not as charismatic as that of Francis, but some cardinals may see that as a plus.

"Parolin is like Clark Kent without the superman part - mild-mannered, industrious, respected, but not flashy," said one person, a layman, who knows him well, referring to the famous comic book character with two personalities.

(Reporting by Philip Pullella; Editing by Frances Kerry)