"The Holy Father died this evening at 9:37 p.m. in his private apartment. All the procedures outlined in the apostolic Constitution `Universi Dominici Gregis' that was written by John Paul II on Feb. 22, 1996, have been put in motion."
The announcement came from papal spokesman Joaquin Navarro-Valls and was distributed to journalists via e-mail.
The pope died after suffering heart and kidney failure after two hospitalizations in as many months.
Just a few hours earlier, the Vatican has said he was in "very serious" condition but had responded to members of the papal household.