Carlo Maria Giulini, 91, the Italian maestro whose rigorous and spiritual interpretations of classical music made him a conducting giant of the 20th century, died June 14 in Brescia, northern Italy. No cause of death was reported.

A young friend of the great Arturo Toscanini's, Mr. Giulini bridged the golden age of conducting and a later generation of such Italian maestros as Riccardo Muti and Claudio Abbado.

He had conducting stints at La Scala, the Chicago Symphony and the Vienna Symphony and was music director of the Los Angeles Philharmonic from 1978 to 1985 -- his last permanent post, which he resigned to spend more time with his ailing wife.

In Los Angeles, where he said his only friend was comedian Danny Kaye, his contract specifically exempted him from any part in the social whirl. That was typical Giulini. A modest, nearly ascetic man, he saw conducting as a priestly mission, a ministry for the gods of classical music.

"We have to deal with genius, and we are small men," he once said.

In his later years, Mr. Giulini stuck close to his home in Milan, conducting Europe's great orchestras but renouncing the opera pit because of the long rehearsals. He concentrated on Brahms, Bach, Mozart, Beethoven, Bruckner and Schubert. For opera, he preferred Mozart, conducting little Puccini or Wagner.

Mr. Giulini's reverence for the masters often produced an almost religious quality in his works. His tempos slowed considerably as he aged.

"Opinion has been divided about his slow tempos, but there is widespread acknowledgment of the exceptional mellowness of his interpretations, the richness of string textures and the seriousness of purpose with which he inspires both instrumentalists and singers," Robert Philip wrote in Mr. Giulini's entry in Grove Music Online.

A number of Mr. Giulini's recordings, especially Verdi's "Requiem" and "Falstaff," are treasured by music buffs, and many Mozart-lovers considered his "Don Giovanni" the best version. Critics also gave Mr. Giulini high praise for his sensitive accompanying on concerto recordings.

Mr. Giulini's search for insight sometimes produced pauses in his career, when he would stay away from the podium for periods of reading, reflection and study.

"Music is an act of love," he would say, dismissing ambition. Career? "The word is repugnant to me," he told an interviewer. "I'm not like a corporal who has to become a captain."

Born in Barletta, near the southern Adriatic city of Bari, on May 9, 1914, Carlo Maria Giulini studied violin and viola. At 19, he won a viola position in the Santa Cecilia orchestra when it played in Rome's Teatro Augusteo.

Because of the theater's spectacular acoustics, it was a regular stop for the age's superstar conductors. Thus Mr. Giulini played under such giants as Wilhelm Furtwangler, Bruno Walter, Willem Mengelberg and Richard Strauss.

Mr. Giulini received a conducting degree in 1941 from the Santa Cecilia conservatory, studying with Bernardino Molinari.

In the years just after the war, Mr. Giulini led the RAI state broadcasting orchestras of Milan and Rome.

The elderly Toscanini heard a Giulini performance and summoned him to his home. The two became friends, an important source of support for the budding conductor.

In 1951, Mr. Giulini took over as principal conductor at Milan's La Scala opera house. His 1956 "La Traviata," with the diva Maria Callas, was memorable.

He made numerous recordings with the major record companies, and won a Grammy Award in 1989.

His wife, Marcella, died in 1995. They had three sons.

Carlo Maria Giulini conducted for La Scala and the Chicago and Vienna symphonies and was music director of the Los Angeles Philharmonic.