LONDON Actor David Tennant is to put down his sonic screwdriver and quit his role as Britain's best-known time traveller "Doctor Who," the BBC said on Thursday.
Tennant, who took over the controls of the Tardis in 2005, will stay on as the Doctor in the special editions of the show in 2009 before a replacement takes over for the fifth new series of the cult science fiction show, the BBC said.
He will also appear in a Christmas special later this year.
"I've had the most brilliant, bewildering and life changing time working on Doctor Who," said Tennant, who described the part as the "best job in the world."
"I have loved every day of it. It would be very easy to cling on to the Tardis console forever and I fear that if I don't take a deep breath and make the decision to move on now, then I simply never will."
"You would be prising the Tardis key out of my cold dead hand."
The Scottish actor is the 10th incarnation of the Time Lord since the show began in 1963, following in the footsteps of the likes of Tom Baker.
He replaced Christopher Eccleston, who took over the role for just one series following its relaunch in 2005 before quitting because he said he did not want to become typecast.
Recently Tennant has been taking a break from Doctor Who to concentrate on stagework, appearing in a critically-acclaimed production of Hamlet earlier this year.
Russell T Davies, the show's executive producer, promised "the most enormous and spectacular ending" for Tennant.
"I might drop an anvil on his head. Or maybe a piano. A radioactive piano," he said.
Speculation has already started as to who will become the new Doctor.
Bookmaker William Hill has David Morrissey, who starred in BBC dramas "Blackpool" and "State of Play," as 5/2 favourite to get the job, followed by Paterson Joseph and James McAvoy.
Other names in the frame include James Nesbitt, best known for comedy drama "Cold Feet," and "Life On Mars" star John Simm.
(Reporting by Michael Holden, Editing by Astrid Zweynert)