Not many people are privy to the thoughts of a world leader, and few journalists have gained the confidence of so many of the world's rich and famous as Frost. He is the only person to have interviewed the last six British prime ministers, as well as the last seven presidents of the US. His landmark one-to-one with disgraced US president Richard Nixon in 1977, in the immediate aftermath of the Watergate scandal, achieved 'the largest audience for a news interview in history', according to the New York Times.

For British audiences, Frost is an institution in his own right, a familiar fixture in the BBC schedule over the years. So there was a considerable buzz around the recent announcement that he is to join Al-Jazeera, a news organisation associated in many Western minds with Osama bin Laden, Al-Qaeda and the conflagration in Iraq. Frost is looking forward to it. 'I like to look for new frontiers, as well as new challenges, and this is very much both,' he says. 'All the people I have met so far have been terrific. Many of them are ex-BBC, so I feel quite at home.'

The veteran broadcaster is one of the jewels in the crown of Al-Jazeera International, a new English-language global channel due to be launched in the spring of 2006. Frost will head up a weekly interview-based show, filmed late enough in London to catch breakfast audiences and interviewees on the east coast of the US. Production will take place at Al-Jazeera's newly acquired London studios: 'Number One Knightsbridge,' says Frost. 'No messing about.' Three other regional bureaus are being set up, in Washington - where ex-CNN anchor Riz Khan will front a show - in Doha and in Kuala Lumpur.

As the exclusive address and high-calibre presenters suggest, Al-Jazeera is certainly not messing about. The new channel will mark the final transformation of the Qatar-based organisation from a lone voice championing freedom of speech in the Middle East, to a fully-fledged global broadcaster. The Arabic-language service has already undergone a facelift. In June, a modern newsroom replaced the cramped quarters used since its launch in 1996. Cooler blue and green graphics have replaced the angry red banners of Al-Jazeera's youth. And a new animated ident has appeared - a golden globe that dips into blue waves before re-emerging as the familiar tear-drop logo.

The company is building on a firm base. Audience figures for the Arabic channel are already estimated at 35 million-40 million, and a recent poll by online magazine Brandchannel voted Al-Jazeera the world's fifth most influential brand. Even so, comparisons with CNN and the BBC are inevitable in the run-up to the launch, and company executives are determined to steer Al-Jazeera out of the long shadows cast by established giants.

'We are not setting ourselves up as competitors to the BBC or CNN; we feel we are fairly unique in what we offer and can leave others to their established markets,' says Al-Jazeera International's managing director, Nigel Parsons. 'We already have the best coverage and contacts in the Middle East. News elsewhere will be decentralised, with Asians covering Asia and Africans covering Africa. And Qatar is a tiny country in terms of world policy, so unlike most broadcasters we can't be said to have a political agenda because of where we're based.'

Competition will be stiff, however. The European Commission gave the green light to Paris in June to set up the French Intern