Arturo sang more than sixty performances with the Metropolitan Opera. His first role with the company was Grigori in the 1963 production of Boris Godunov. Other roles he performed with the Met included Turiddu in Cavalleria Rusticana, Radams in Aida, Lohengrin, Alfred in Die Fledermaus, and Jacob Schmidt in the 1984 production of The Rise and Fall of the City of Mahagony, his last Met appearance.
Sergi also sung major roles at Covent Garden, Hamburg, Frankfurt, and Bayreuth. In 1970, he joined the voice faculty at the University of Texas at Austin. His final appearance was in the title role of The Mikado at Wichita Grand Opera in 2004.
Sergi was 80 years old, and died in Austin, Texas.