* Father Puglisi shot by Mafia in 1993
* Considered a martyr by Catholic church
* Beatification is step before sainthood
ROME, May 25 (Reuters) - A Sicilian priest gunned down by the Mafia twenty years ago outside his home in Palermo was beatified in a seafront ceremony on Saturday attended by an estimated 100,000 people from all over Italy.
Father Giuseppe Puglisi was shot in the back of the head in September 1993 in the crime-ridden Brancaccio district of the Sicilian capital where he preached against the Mafia.
School parties, local dignitaries and top government ministers braved a stiff wind as the emeritus archbishop of Palermo read out the formal letter of beatification from Pope Francis in Latin.
Francis's predecessor, Pope Benedict, put Puglisi on the fast track towards sainthood in the Roman Catholic Church when he signed a decree last year recognising that Puglisi had been killed "in hatred of the faith."
That meant he could be beatified - the last step before sainthood - without a miracle being attributed to his intercession with God. A miracle is required for him to be declared a saint, however.
A huge photo of Puglisi was unveiled as white doves were released in the two-hour ceremony in a vast square surrounded by palm trees. He was repeatedly referred to as a "martyr" who paid for his constant preachings against the Sicilian mob.
He was killed for "depriving the Mafia of support, manpower and control of the city" with his large following in Palermo, said Cardinal Paolo Romeo, the primate of Sicily who presided over most of the ceremony.
Many of the faithful wore T-shirts with photos of Puglisi, who was killed on his 56th birthday after serving in Palermo for 33 years.
Italian President Giorgio Napolitano said in a statement that Puglisi "continues to be an example for all those who refuse to give in to the power of organised crime."
Six mafiosi were sentenced to life in prison for the murder, which took place a year after the high-profile killings on the island of anti-Mafia prosecutors Giovanni Falcone and Paolo Borsellino, at a time when the Sicilian mafia was particularly ruthless.
The Sicilian Mafia, known as Cosa Nostra, is probably the best known of Italy's three main criminal organisations, but in the last two decades many of its top bosses have been captured.
The Camorra, which operates around the southern port of Naples, and the 'Ndrangheta, based in the most southerly mainland region of Calabria, are now considered to be more powerful. (Reporting by Gavin Jones; Editing by Sonya Hepinstall)