Veteran BBC broadcaster and writer Alistair Cooke has died at his home in New York.
Cooke had a long and distinguished broadcasting career
For 58 years, Cooke presented his radio series Letter from America, the world's longest-running speech radio programme.
Earlier this month, he announced his retirement on health grounds following advice from his doctors.
Leading the tributes, Prime Minister Tony Blair described him as "a remarkable man" and "one of the greatest broadcasters of all time".
The BBC's acting director general, Mark Byford, said Cooke was "one of the greatest broadcasters ever in the history of the BBC".
A BBC spokesman said Cooke's daughter contacted his biographer, BBC reporter Nick Clarke, to confirm his death at midnight local time (0600 BST).
Cooke was absent from recent shows due to illness, and this month it was announced he would not record any new Letters.
The BBC said Cooke had decided to sign off following advice from doctors. His final Letter was broadcast on 20 February.
In it, he talked about being "propped up there against my usual three pillows" before considering how Iraq and domestic issues had become key elements in the run-up to the US presidential elections.
"Throughout 58 years I have had much enjoyment in doing these talks and hope that some of it has passed over to the listeners, to all of whom I now say thank you for your loyalty and goodbye," he said.
Cooke joined the BBC as a film critic in 1934 and started writing his US current affairs and historical Letter in 1946.
The show was listened to by people across Europe, Asia, New Zealand, Africa, the Americas and the Middle East via the BBC's World Service. It was heard in the UK on BBC Radio 4.
Over almost 60 years, his 15-minute reflections touched on everything from the assassinations of the Kennedys to the terrorist attacks of 11 September.
One of his most memorable accounts came when he happened to be in the Los Angeles hotel where Bobby Kennedy was shot in 1968.
He told listeners: "Down on the greasy floor was a huddle of clothes, and staring out of it the face of Bobby Kennedy, like the stone face of a child, lying on a cathedral tomb."
Cooke had presented 2,869 shows, missing just three weekly broadcasts during the Letter from America's run.
Cooke (right) presenting American Half Hour in 1935
These made up more than 717 hours of broadcasting time. This figure does not include other radio shows he hosted.
Radio 4 controller Helen Boaden said millions of listeners "charted our lives through" his accounts.
"He was wry, wise and always insightful," she said. "We shall miss him very much."
Cooke, born in Salford, near Manchester, in 1908, lived with his second wife Jane White in New York.
In 1973, he received an honorary knighthood for his contribution to Anglo-American understanding, and a year later addressed the United States Congress on its 200th anniversary.
He also received an award from Bafta for his contribution to Anglo-American relations and a Sony Radio Award for his services to broadcasting.
On TV, he presented Alistair Cooke's America, which was aired around the world.
And his ground-breaking cultural television show Omnibus changed the face of US television in the 1950s.
A special one-hour tribute, Remembering Alistair Cooke will be broadcast on BBC Radio Four at 2100 BST on Tuesday 30 March, 2004 and at 2000 BST on Saturday 3rd April, 2004.
A World Service tribute is being broadcast at 1030 GMT, 1430GMT (not Europe) and 2130 GMT (Europe) on Tuesday 30 March, 2004.