Pope Benedict XVI may issue a decree that would bring forward the conclave tasked with electing his successor before a date in mid-March scheduled under the current rules, the Vatican says.
"The Pope is considering a Motu Proprio (decree) in the coming days... to clarify a few specific aspects of the apostolic constitution on the conclave," spokesman Federico Lombardi said on Wednesday.
Historian Ambrogio Piazzoni said "the Pope is the only one who can legislate until the last minute", when he steps down on February 28.
The Apostolic Constitution promulgated by Benedict's predecessor, the late Pope John Paul II, in 1996 states that the conclave must begin between 15 and 20 days following the start of the popeless "Sede Vacante" ("Vacant Seat") interregnum.
The delay is normally for cardinals to have time to travel to Rome following the death of a Pope.
But in this case many of the cardinals are already in Rome to bid farewell to the outgoing pontiff.
The conclave is expected to bring together the world's 117 "cardinal electors" and meets in secret in the Sistine Chapel until a two-thirds majority is found in favour of a candidate to be the Pope.
Bringing forward the date of the start of the conclave would help prevent any overlap with Easter, which this year falls on March 31.