SAN FRANCISCO - APPLE chief executive Steve Jobs underwent a liver transplant at a Tennessee hospital and has 'an excellent prognosis', the hospital that performed the operation confirmed on Tuesday.

Jobs, 54, received the transplant because he was 'the sickest patient on the waiting list at the time a donor organ became available,' the Methodist University Hospital Transplant Institute said in a statement on its Website.

'Mr Jobs is now recovering well and has an excellent prognosis,' the statement said. James Eason, program director at the institute and the hospital's chief of transplantation, added that the confirmation had come with Jobs's permission.

The hospital did not release details of Mr Job's condition or when the operation was performed, but the Wall Street Journal reported over the weekend that the transplant took place about two months ago.

Hospital spokeswoman Ruth Ann Hale did not immediately respond to a request for comment on Mr Jobs' condition. A prognosis refers to a doctor's prediction regarding the probable course of a disease, disorder or injury.

The executive, considered by many investors to be the driving force behind Apple's reputation for innovation, was treated in 2004 for a rare form of pancreatic cancer called an islet-cell, or neuroendocrine, tumor.

But he appeared gaunt at an Apple event in the summer of 2008, setting off a storm of speculation about his health that failed to abate in the ensuing months.

In January, after initially blaming his weight loss on a hormone imbalance, he announced his medical leave, saying his health issues were 'more complex' than originally thought.

He has not been heard from since, though a witness spotted Mr Jobs at Apple's campus in Cupertino, California, on Monday and Mr Jobs was quoted in a company press release.

The company would not say whether Mr Jobs is off medical leave and back at work. Apple has said repeatedly that it looks forward to his return at the end of June. -- REUTERS