Herbert Breslin began working with the Italian singer in 1967, six years after he made his professional debut.

But he said their working relationship had come to an end this week.

"We no longer work for each other," Mr Breslin said.

"We've had enough. I've had enough."

Mr Breslin is credited with helping Pavarotti build-up a following outside of the classical music world, with sell-out arena concerts and television appearances.

Pavarotti, 67, helped bring classical music to a new audience largely due to his rendition of Nessun Dorma with José Carreras and Placido Domingo, which was the soundtrack to the 1990 World Cup.

Pavarotti's opera performances have become limited

But Pavarotti has been concentrating less on performing in large scale operas.

His last major performance was in Puccini's Tosca at the Royal Opera House in London in January 2002.

"Most of Pavarotti's appearances haven't been operas or recitals," his spokeswoman, Terri Robson, said.

Retirement

"He's been doing less and less. Herbert's work has been limited to Pavarotti's opera and recital appearances.

"Luciano has two other offices, and most of his work has been coming out of Italy, not New York."

Pavarotti cancelled his past two performances at New York's Metropolitan Opera, saying he had flu.

He has already indicated he plans to retire from singing on 12 October, 2005, the day of his 70th birthday.

His next performance is scheduled in the US for September, when he is due to join Domingo and Carreras in a Three Tenors concert in Ohio.

It had been planned for 5 January but was postponed because Pavarotti's partner, Nicoletta Mantovanis, is expecting to give birth to twins around that date.

Pavarotti already has three children from his first marriage to Adua Veroni.