Image caption Who Wants To Be A Millionaire? has been sold to more than 100 countries

Theme tunes from shows like The Weakest Link and Who Wants To Be A Millionaire? have been among the UK's most lucrative musical exports over the last decade.

TV was one of the biggest growth areas for British songwriters and composers between 2000 and 2009, with revenues rising from £15m to £50m.

Theme tunes and scores made up the "lion's share" of those sums, according to songwriters' body PRS For Music.

They contributed to a rise in overall global earnings from £66m to £166m.

Royalties from radio airplay have grown from £22m to £39m, while revenues from live performances have leapt from £1.5m at the start of the decade to £18m last year.

'Buoyant' year

The writers of theme tunes and incidental music for TV shows get paid every time that music is used anywhere around the world.

Successful British writers include father-and-son team Matthew and Keith Strachan, who were behind the music for Who Wants To Be A Millionaire?

That show has been remade in more than 100 countries since it was first seen in the UK in 1998.

Paul Farrer wrote the music for The Weakest Link, which has also been sold to around 100 countries, while Andrew McCrorie-Shand - former member of the prog rock band Druid - composed the Tellytubbies theme.

"When we have exports of TV programmes that are exported around the world, we're getting better at tracking down that revenue, working out what's been broadcast," said Karen Buse, PRS For Music director of international.

And revenues from live music benefited from a "buoyant" year in 2009, she said.

"We had some big bands, particularly in Europe and South America, going to very large stadia," she said. "We get very good rates from concert promoters in these territories.

"We've been more proactive in making sure we're aware of every single broadcast and every single performance."