* Pope elevates 22 prelates to high rank of cardinal
* 18 are cardinal electors allowed to choose next pope
* Among prominent are New York's Dolan, Hong Kong's Tong
By Philip Pullella
VATICAN CITY, Feb 18 (Reuters) - - Pope Benedict, putting his mark on the Catholic Church's future, on Saturday inducted 22 men into the exclusive club of cardinals who will one day elect one of their own to succeed him.
Among the most prominent in the group is New York's Archbishop Timothy Dolan, who is already being touted by some Vatican experts as a possible future candidate to become the first American pope.
Benedict, who turns 85 in April and is showing signs of his age, elevated the men to the highest Church rank below him at a ceremony in St. Peter's Basilica known as a consistory.
"Cardinals are entrusted with the service of love: love for God, love for his Church, an absolute and unconditional love for his brothers and sisters, even unto shedding their blood, if necessary (in defence of the faith)," the pope told the new cardinals before giving them their rings and red birettas, or hats.
"Furthermore, they are asked to serve the Church with love and vigour, with the transparency and wisdom of teachers, with the energy and strength of shepherds, with the fidelity and courage of martyrs," he said.
The new cardinals are from the United States, Hong Kong, Italy, Portugal, Spain, Brazil, India, Canada, the Czech Republic, the Netherlands, Romania, Belgium, and Malta.
Eighteen of them are aged under 80 and thus will be eligible to enter a secret conclave to elect the next pope from among their own ranks.
Twelve of those are Europeans, bringing the number of "cardinal electors" from the continent to 67 out of 125.
With the new appointments, Benedict, who was elected in a secret conclave in 2005, has now named more than half the cardinal electors. The others were named by his predecessor John Paul.
Compared to the 67 "cardinal electors" from Europe, Latin America now has 22, North America has 15, Africa has 11, Asia has 9 and Oceania has one.
Cardinals are the pope's closest collaborators in the Vatican and around the world. They lead major archdioceses and run key Vatican departments that help the pope decide Church policy and doctrine that can affect the lives of world's 1.3 billion Roman Catholics.
FIRST, BE MEN OF RELIGION, POPE TELLS NEW CARDINALS
At the ceremony, the pope told the new cardinals that while they will cooperate closely with him in "the delicate task" of governing the worldwide Church, they must first and foremost be men of religion.
"May your mission in the Church and the world always be "in Christ" alone, responding to his logic and not that of the world, and may it be illumined by faith and animated by charity which comes to us from the glorious Cross of the Lord," he said.
Benedict also asked for prayers so that he can guide the Church "with a firm and humble hand".
The consistory, usually a joyful event, is taking place under a cloud because it follows a spate of leaked letters alleging corruption in the Vatican.
Numerically, at least, the pope has increased the chances that the next pontiff will be a conservative European but there have been surprises in past conclaves.
The pope is a conservative on matters of faith and sexual morals such as birth control, homosexuality and the ban on women priests. Each time he names cardinals he puts his stamp on Roman Catholicism's future by choosing men who share his views.
Besides Dolan, other prominent new cardinals are John Tong Hon, archbishop of Hong Kong, and Rainer Maria Woelki, archbishop of Berlin in the pope's native Germany.
Seven of new "cardinal electors" under the age of 80 are Italian - six of them members of the Vatican's central administration and the other the archbishop of Florence.
Popes usually reign for life but in a book last year, Benedict said he would not hesitate to become the first pontiff to resign willingly in more than 700 years if he felt himself no longer able, "physically, psychologically and spiritually", to run the Catholic Church.
Several popes in recent history, including the late Pope John Paul, considered resigning for health reasons, but none did so.
The last pope to resign willingly was Celestine V in 1294 after reigning for only five months. Gregory XII reluctantly abdicated in 1415 to end a dispute with a rival claimant to the Holy See.
The Vatican says the pope's health is good but he needs to conserve his strength. Last October he started using a mobile platform which aides use to wheel him up the central aisle of St Peter's Basilica. (Reporting By Philip Pullella; Editing by Alistair Lyon)
New Cardinals Represent Pope's Vision For Church's Future