The UK's Digital Radio Development Bureau predicts that sales of digital radio receivers will soar over the next five years.

Its latest figures forecast that 18 million digital radio sets will be in British homes by the end of 2009 - a 1,500% increase on the beginning of this year.

DRDB, a trade body funded by broadcasters, predicts the retail market will be worth around £456m ($833m; €668m) annually by 2009 - compared with £87m last year.

Car drivers are expected to be major consumers of digital radio services, with the number of receivers fitted in vehicles projected to increase to 700,000-plus by 2009, up from 15,000 units this year.

Innovations such as electronic program guides and the addition of multimedia and interactive services are also expected to boost digital radio popularity.

Says DRBB chairman Ralph Bernard: "The latest figures . . . show that DAB digital radio continues its healthy climb to mass market penetration in the UK."

Data sourced from MediaGuardian.co.uk; additional content by WARC staff