Vandross has sold more than 20 million records around the world

Soul singer Luther Vandross has had a throat operation to fight off pneumonia, two weeks after suffering a stroke.

Vandross has undergone a tracheotomy, a procedure to allow him to breathe, his manager said on Monday.

But it was done in a way that did not affect the vocal chords.

The singer's business manager Carmen Romano said doctors had reported minimal responses since the stroke.

"We're waiting for him to regain full consciousness," she said. "I am told that this may take some time."

She added that the family and friends appreciated the "tremendous outpouring of well wishes and prayers" sent by fans.

'Good health'

The Grammy-winning singer has been in hospital in New York since falling ill at his home in Manhattan on 16 April.

Vandross was said to have been in good health before the stroke.

Vandross, who has sold more than 20 million records worldwide in his career, won four Grammy awards in the 1990s.

His hits include Jump to It, Here and Now, and Don't Wanna Be a Fool.

Apart from his own singing and writing, he has produced for other stars, including Aretha Franklin, Dionne Warwick, Diana Ross and Whitney Houston.

Eating problems

Vandross has battled weight problems and admitted once hitting the scales at well over 300 pounds.

He has also suffered from hypertension and diabetes.

"If I'm emotionally distraught, then eating is my coping mechanism", he told Britain's Q magazine in 1991.

He said in 2001 that he was planning to write a book about his most successful attempts to shed weight.