al-Jazeera has signed up Sir David Frost as a key face of its new English-language news channel.

The veteran broadcaster, who stepped down from his Sunday morning breakfast show with the BBC earlier this year, had been courted by the controversial Arabic station for some time.

"We are thrilled to have Sir David Frost join Al Jazeera International," said Nigel Parsons, the channel's managing director. "He's a one-man international broadcasting phenomenon and our viewers can look forward to the substance and quality that have marked his distinguished career."

Details of Frost's role are unknown, although he is expected to continue with other BBC projects, including hosting a new series of Through The Keyhole.

"This is a great adventure – the first and perhaps the only brand-new international TV news network for the 21st Century," said Frost. "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 6 billion other inhabitants of the globe. As someone said, a new show for a new channel for the new century."

al-Jazeera International is due to launch next Spring.