NEW YORK – Beverly Sills, the opera diva who won over fans worldwide with her sparkling voice and charming personality and later became a powerhouse in the New York arts world, is ill with cancer.

Sills, 78, was chairwoman of the Metropolitan Opera until she resigned two years ago, citing health and family reasons. She remains the Met’s chairwoman emerita. The Met would neither confirm nor deny news of her illness, but people close to the situation said Sills was at a Manhattan hospital.

In an e-mail this week to members of its board, the Met said Sills was “gravely ill.” One person said she was suffering from lung cancer.

Sills, a nonsmoker, underwent successful cancer surgery in 1974.

Born Belle Miriam Silverman in Brooklyn, the coloratura soprano became a star with the New York City Opera, where she first performed in 1955 in Johann Strauss Jr.’s “Die Fledermaus.” She didn’t appear at the Met until 1975, shortly before her retirement from singing – which made it surprising when the Met asked her to sit on its board in 2002.