* Italy PM says world of music has lost a champion
* Abbado shunned pomp and publicity, supported young musicians
* Conducted in world's great music capitals (Adds detail and prime minister, mayor reaction)
MILAN, Jan 20 (Reuters) - Claudio Abbado, one of the world's top conductors who over the decades led the Berlin Philharmonic Orchestra, Vienna's State Opera and Milan's La Scala, has died aged 80, the Milan opera house said on Monday.
Abbado, who shunned the publicity and pomp often associated with grand maestros and staunchly supported young musicians, died in the northern city of Bologna in his native Italy after a long illness.
"The world of music and culture has lost an absolute champion," Italian Prime Minister Enrico Letta said in a statement.
Milan mayor Giuliano Pisapia said he would ask La Scala's current director to organise a memorial concert for Abbado, who was ceremonially named an Italian Senator for Life by President Giorgio Napolitano last August.
Abbado's surprise appointment as chief conductor of the Berlin Philharmonic in 1989 led music critics to call him "the world's most powerful conductor". He also had a 46-year span recording some of the world's most cherished performances for the Deutsche Grammophon label.
Born in Milan on June 26, 1933, to a violinist father and a pianist mother, Abbado announced his intention of becoming a conductor when he was eight years old.
He earned pocket money as a church organist before joining the Vienna Academy of Music in 1956. In Vienna, Abbado learned an economical style of conducting and Hans Swarovsky taught him to conduct with one hand tied behind his back.
Abbado's rhythmic energy, drive and love of big, colourful sound placed him squarely in the tradition of late fellow-Italian Arturo Toscanini.
During his time at la Scala, Abbado rejigged the usually staid repertory and encouraged young people and less wealthy music lovers to join the well-heeled crowd in the auditorium.
Conservative audience members left their seats in protest at Abbado's addition of avant-garde composers such as Italians Luigi Dallapiccola and the communist Luigi Nono to the repertory.
Abbado also worked to support young musicians, becoming founding music director of the European Union Youth Orchestra.
"What I like to remember about Abbado is his commitment to fostering young talent," Pisapia said in a statement on Monday.
Abbado was diagnosed with cancer in 2000, but recovered and three years later went on to form the Lucerne orchestra, selecting most of the members himself.
La Scala was forced to cancel concerts when Abbado succumbed to another bout of illness in May 2010.
Abbado also worked in the United States, often serving as guest conductor of the New York Philharmonic, the Cleveland Orchestra and the Philadelphia Orchestra. He was principal conductor of the London Symphony Orchestra in the 1980s. (Reporting by Sara Rossi and Isla Binnie; Writing by Isla Binnie; Editing by Sonya Hepinstall and Michael Roddy)