Broadcasting company MediaWorks, which operates TV3 and C4, is launching a second music channel titled C42 with plans to play "up to" 30 per cent New Zealand content.

The channel will be available only on Freeview following its launch on May 1 - the first day of New Zealand Music Month.

Mediaworks said C42 would play music 24 hours a day and was designed to complement C4, which had moved on from its music television origins and was now a "general youth entertainment channel".