Frost will join Al Jazeera, the first English-language news channel based in the Middle East, from its launch next spring. Details of his new role at the channel are unknown.
Frost said: "Most of the television I have done over the years has been aimed at British and American audiences. This time, while our target is still Britain and America, the excitement is that it is also the 6bn other inhabitants of the globe. As someone said, a new show for a new channel for the new century."
Most recently, Frost finished his BBC Sunday morning politics show 'Breakfast with Frost' and has been a relatively free agent since -- although speculation that Al Jazeera was courting the presenter surfaced in August.
He is expected to continue with other BBC projects, including big-name interviews and hosting a new series of 'Through the Keyhole'.
Al Jazeera International will operate from Doha in Qatar. It will be available globally, and will also have a London office and bureaux in Kuala Lumpur and Washington.
Frost's presence could help the channel overcome antipathy from the UK and US governments, with whom Al Jazeera's existing Arabic channel is out of favour.
During the war in Iraq, the channel was condemned by London and Washington for alleged biased reporting and screening images of dead and captured coalition troops. Al Jazeera was then banned from operating its Iraq office by the interim Iraqi administration.
"This is a great adventure -- the first and perhaps the only brand-new international TV news network for the 21st century," Frost added.
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