Rome (CNN) -- More than 140 Catholic cardinals met Monday at the Vatican, where the process of selecting a new pope edged toward beginning.
The cardinals met twice during the day, in the morning and in the evening. After the evening session, most left by car, though some departed on foot. Few spoke as they left the meeting.
After the morning session, a decision had not been made on when the conclave to select Pope Benedict XVI's successor would start, Vatican spokesman the Rev. Federico Lombardi told reporters.
"It's on the table, but no decision has been reached," Lombardi said.
The General Congregations meeting is a key step before the conclave, in which all cardinals younger than 80 are to meet in the Vatican to vote for the next pope.
Of the 142 cardinals who attended Monday morning's session, 103 were cardinal electors, Lombardi said. Another 12 cardinal electors were expected to arrive later Monday and Tuesday, he said.
During the afternoon meeting, four more cardinals joined those who had already been here; the group decided that congregations on Tuesday and Wednesday would take place in the morning only, he added.
And the Rev. Raniero Cantalamessa, preacher to the Pontifical Household, held the first meditation as outlined by the Apostolic Constitution, Lombardi said.
Benedict announced his intention to step down on February 11 and resigned Thursday, becoming the first pope to do so in 600 years. The transfer of papal power has almost always happened after the sitting pope has died.
Normally, the College of Cardinals is not allowed to select a new pontiff until 15 to 20 days after the office becomes vacant. However, Benedict amended the 500-year-old policy to get a successor into place more rapidly.
The cardinals may to be able to do so before March 15, Lombardi has said.
This would give the new pontiff more than a week to prepare for the March 24 Palm Sunday celebrations.
Some gambling houses are offering odds on who will next lead the Catholic Church.
Favorites include the archbishop of Milan, Italy, Cardinal Angelo Scola; Cardinal Tarcisio Bertone of Italy; Cardinal Peter Turkson of Ghana, who would become the first African pontiff since Pope Gelasius I died more than 1,500 years ago; and Cardinal Marc Ouellet of Canada, who would become the first North American pope.
One former cardinal who won't participate in the conclave is Keith O'Brien of Scotland, who resigned last month. O'Brien apologized Sunday for sexual impropriety, without specifying any incident. "To those I have offended, I apologize and ask forgiveness," he said in a statement.
The Vatican refused to answer questions on Monday about whether it will discipline O'Brien. In response to questions from British journalists, Vatican spokesman the Rev. Thomas Rosica read the statement that O'Brien released on Sunday.
"That is all we can say, is what's been said," Rosica said.
But others did comment. "It looks as if the incidence of abuse is practically zero right now as far as we can tell, but they are still the victims and the wound therefore is deep in their hearts and minds very often," Cardinal Francis George, archbishop of Chicago, told reporters in Rome. "As long as it's with them, it's with all of us and that will last for a long time, so the next pope has to be aware of this."
Philip Tartaglia, the archbishop of Glasgow and apostolic administrator of the Archdiocese of St. Andrews and Edinburgh, will administer O'Brien's archdiocese until a new appointment is made.
"The most stinging charge which has been leveled against us in this matter is hypocrisy, and for obvious reasons," Tartaglia said in prepared remarks slated for delivery Monday night in his sermon at St. Andrew's Cathedral in Glasgow. "I think there is little doubt that the credibility and moral authority of the Catholic Church in Scotland has been dealt a serious blow, and we will need to come to terms with that."
He added, "As for the Church's mission in our country, yes, our credibility and moral authority have been undermined. It will take time, perhaps a long time, to recover these intangible but important realities. But we cannot be defeatist. The answer to this sad episode is not to throw in the towel. We need, rather, to renew our faithfulness to Jesus Christ and to go about our business humbly."
While Benedict has no direct involvement in the selection of his successor, his influence will be felt: He appointed 67 of at least 115 cardinals set to make the decision.
Cardinals must vote in person, via paper ballot. Once the process begins, the cardinals aren't allowed to talk with anyone outside of the conclave. They cannot leave until white smoke emerges from the Vatican chimney -- the signal that a new leader has been picked.
Lombardi said Monday that 4,300 journalists have been accredited to cover the papal conclave.
CNN's Richard Allen Green reported from Rome. CNN's Mark Morgenstein reported from Atlanta. CNN's Catherine E. Shoichet contributed to this report.