The departure of the veteran broadcaster from the news programme would be a blow to the BBC, which has recently suffered the defections of several high-profile presenters.
Yesterday Mr Humphrys told The Independent that he was considering a "radical change" when his contract expires next spring. "I have no more job ambitions in broadcasting," he said. "If I was offered an interview with the Queen, that would be good, but I am fulfilled in terms of my broadcasting career."
Mr Humphrys was speaking in Edinburgh where he was promoting his first book, Devil's Advocate, which is about consumerism and moral values in Britain.
Last week the BBC presenter, a former television news reader, caused controversy by criticising the corporation's 6 o'clock television news for taking too "cosy" an approach.
He also upbraided a new breed of "friendly" journalists who, he said, were afraid to put difficult questions to public figures in a misguided desire to offer a "cosy" view of life.
Yesterday he said that he intended to retire from Today, where he has been the main presenter since the death of Brian Redhead, or scale down the amount of work he does for it. "It's a case of how little you can do, still be a presence and still be important. Three or four days a fortnight would be attractive but too little from an editor's point of view."
He added: "The problem isthat even with less work, you still need to read all the papers all the time and stay in touch. You can't go on holiday without staying in touch."
Mr Humphrys said that he would like to spend more time writing but, although he is seeking an organic farm to buy, he is "not quite ready" to retire to the country.
Pressure is now on the BBC to come up with a package that would allow Mr Humphrys to balance a smaller amount of broadcasting with his other activities. A BBC manager said: "There's been a wave of desertion from the BBC, both on screen with the likes of Des Lynam and Barry Norman and off screen. It is important that we find new ways of encouraging people to stay."
Mr Humphrys also presents BBC1's On the Record programme and On the Ropes on Radio 4. However it is the Today programme, on which he has worked for 13 years, that takes up most of his broadcasting life.
Responding to a BBC view that Mr Humphrys is joining Jeremy Paxman as one of broadcasting's "statesmen" he said yesterday: "I suppose it's quite nice if I can say what I think without being sacked." The BBC is also facing the loss of its chief weather forecaster, Bill Giles. Mr Giles, 59, who has been with the BBC for 25 years, says he is fed up with cutbacks, most notably the scrapping of The Weather Show on BBC2. "I came here to present the weather, but now I spend more time on internal politics," he said at the weekend.