The BBC Trust is to support the introduction of a high-definition BBC channel, and will consult the public about the plans.

The news comes just a week after Ofcom gave the green light for the BBC to start broadcasting in high definition via Freeview.

The BBC governing body has concluded that a BBC HD channel for Sky satellite, cable, Freeview and the internet would offer "high public value" and cause a minimal adverse impact on the market.

A trial version of the channel, which includes BBC content such as Planet Earth and Bleak House, was launched last year on satellite and cable. The Trust has decided that the channel should continue to run when a full service licence is granted.

A four-hour service could launch "almost immediately" on Freeview, following public consultation, but viewers would have to buy a new set-top box to receive the channel.

The consultation is now open, and viewers are invited to air their views online at the BBC Trust HDTV – public consultation website. Consultation closes on 23 October, and the Trust will publish its conclusions on 21 November.

Channel 4 announced last week that it will be the first UK terrestrial broadcaster to air its output in HD. The broadcasts will be available in high definition from later this year to viewers with a compatible TV and Sky HD box.