The ABC is making major changes to its radio line-up next year, with iconic Classic FM host Margaret Throsby ending daily broadcasting and former News Corp Australia chief executive Kim Williams joining the public broadcaster as a regular presenter.

The biggest changes are at Radio National, which will cancel almost all its music programming and give more prominence to conservative voices. Up to seven staff could lose their jobs in the changes.

Throsby, who has hosted the Midday program on ABC Classic FM since 1994, will leave weekday radio to host a three-hour program on Saturday morning.

The Midday program, in which guests share their life stories and select their favourite music, will not return in 2017.