Cardinals will begin holding formal meetings starting March 4 as part of their preparations for a conclave to elect the new pope, the Vatican said Friday.

The first meeting will be held at 9:30 a.m. Monday at the Synod of Bishops hall in the Paul VI Audience Hall, used by the pope for general audiences during winter and on rainy days.

Cardinal Angelo Sodano made the date and time official on Friday, just hours after Benedict XVI stepped down and the church entered into a period known as the Sede Vacante, or Vacant See, the transition between the end of one papacy and the start of another.

Some 144 cardinals have already gathered in Rome, but Vatican rules state that they must be formally instructed to make preparations for the conclave.

Participants at Monday's meeting will discuss when to hold the conclave, as well as debate different problems facing the church and possible solutions.

Benedict XVI, the 265th successor to St. Peter at the helm of the Catholic Church, left the papacy on Thursday to become a simple "pilgrim who is starting the last phase of his pilgrimage on this earth."

The German pontiff, who turns 86 in six weeks, began his last day as the leader of the world's more than 1 billion Catholics by bidding farewell to the College of Cardinals and vowing "unconditional obedience to the new pope."

Under the Holy See's constitution, the conclave should begin between 15 and 20 days after the papacy becomes vacant to give time for all of the cardinals to arrive in Rome. EFE