Photo: The Canadian Press. All rights reserved.

Workers sets up a stage for the media next to St Peter's Square ahead of Pope Benedict XVI's last public audience Wednesday, at the Vatican, Tuesday, Feb. 26, 2013. Pope Benedict XVI has changed the rules of the conclave that will elect his successor, allowing cardinals to move up the start date if all of them arrive in Rome before the usual 15-day transition between pontificates. (AP Photo/Oded Balilty)

Pope Benedict XVI will be known as "emeritus pope" in his retirement and will continue to wear a white cassock, the Vatican announced Tuesday, again fueling concerns about potential conflicts arising from having both a reigning and a retired pope.

The pope's title and what he would wear have been a major source of speculation ever since Benedict stunned the world and announced he would resign on Thursday, the first pontiff to do so in 600 years.

The Vatican spokesman, the Rev. Federico Lombardi, said Benedict himself had made the decision in consultation with others, settling on "Your Holiness Benedict XVI" and either emeritus pope or emeritus Roman pontiff.

Lombardi said he didn't know why Benedict had decided to drop his other main title: bishop of Rome.

In the two weeks since Benedict's resignation announcement, Vatican officials had suggested that Benedict would likely resume wearing the traditional black garb of a cleric and would use the title "emeritus bishop of Rome" so as to not create confusion with the future pope.

Benedict's decision to call himself emeritus pope and to keep wearing white is sure to fan concern voiced privately by some cardinals about the awkward reality of having two popes, both living within the Vatican walls.

The first meeting isn't now expected until Monday, Lombardi said, since the official convocation to cardinals to come to Rome will only go out on Friday, the first day of what's known as the "sede vacante," or the vacancy between papacies.

In all, 115 cardinals under the age of 80 are expected in Rome for the conclave to vote on who should become the next pope; two other eligible cardinals have already said they are not coming, one from Britain and another from Indonesia. Cardinals who are 80 and older can join the College meetings but won't participate in the conclave or vote.