The economy of docs is more fragile than it was five years ago,' says Nick Fraser, one of the world's key players in the field as the editor of the BBC's Storyville, the public broadcaster's renowned international documentary strand. 'The promise has been fulfilled in the quality of titles but not always in the box office. Also, all the broadcasters are under pressure.'

Fraser has first-hand experience of fragile economics: in 2007, the BBC threatened to cut Storyville's annual budget in half, from about $3.8m to $1.7m (£2.2m to £1m.) In uproar, the film-making community in the UK and beyond started a 'Save Storyville' campaign. Luckily, the budget was not slashed by that much - now starting at about $2.6m (£1.5m) annually - and, Fraser notes happily, 'we can go and find extra money within the BBC for other special projects'.

Storyville backs around 25 documentaries a year, down from 38 in recent years. 'So the per-show investment isn't lower than before,' Fraser notes. And with a staff of just four, 38 films a year left resources stretched. 'Now we have more time to devote to each project.'

The Storyville strand will run on BBC4 on Monday nights, with occasional films also showing on BBC2. The new season kicked off this month with Marina Zenovich's Roman Polanski: Wanted And Desired, one of six Storyville films that screened in competition at Sundance.

Another Storyville-backed Sundance title, James Marsh's multiple-award-winning Man On Wire, shows the kind of theatrical reach TV-funded documentaries can have (Storyville has UK TV rights to its films but encourages theatrical exposure at home and abroad).

'There are very few stories that can elicit that kind of feeling,' Fraser says of Man On Wire, about Philippe Petit's awe-inspiring highwire walk between the World Trade Center's Twin Towers in 1974. 'We have to try to find more things like that. I feel embarrassed sometimes that I haven't come up with more Man On Wires.'

Of course, Fraser has had his share of hits since starting Storyville at the BBC in 1997, including Born Into Brothels, Bus 174, Crumb, Etre Et Avoir, Lost In La Mancha, One Day In September, Tarnation, The War Room and Why We Fight.

Storyville can acquire finished films but also gets involved at an early stage, often as a co-producer in the patchwork world of international documentary funding. 'We can't always offer enough money but we can put in the clout of the BBC,' he says.

As one of the international scene's key commissioners, Storyville sees around 1,500 submissions and pitches per year. He attends key documentary festivals including the UK's Sheffield Doc/Fest, Idfa in Amsterdam and Hot Docs in Toronto, as well as Sundance, Berlin, Tribeca and Toronto.

Fraser says he is constantly inspired by the new ideas presented to him, both in terms of pitches and ideas for digital distribution of documentaries, which he believes could help with those changing economics of production funding.

His aim is to make Storyville films even more entertaining - even those tackling serious subjects. 'There are plenty of gruelling documentaries but not enough that are charming and intelligent,' Fraser says. 'Even if a subject is awful, you can find energy and verve in it.'

Upcoming titles include Mercedes Stalenhoef's When Borat Came To Town, about the Romanian town outraged at its depiction in the Borat movie; Liz Mermin's inside-Bollywood portrait Shot In Bombay; Stefan Forbes' Boogie Man: The Lee Atwater Story, about the pivotal US Republican political figure; and Kimberly Reed's Prodigal Sons, about an American football hero who has gender reassignment surgery.

Projects in the works include an Israeli film about the search for a reincarnated holy figure; a history of the US Army's 7th Cavalry; the story of a raucous Lagos-based family; and, with regular partner HBO, the story of the late United Nations diplomat Sergio Vieira de Mello.

NICK FRASER'S CULTURAL LIFE

Favourite recent films: Persepolis; 4 Months, 3 Weeks & 2 Days

Favourite recent books: The Dark Side by Jane Mayer, Liars In Love by Richard Yates

Daily reading: The Observer, Harper's, The Economist.