Ofcom has given the green light for the BBC to start broadcasting in high definition via the Freeview service.

The comms regulator said in a Market Impact Assessment that the BBC's free offering would not disrupt the market and that any impact on commercial providers is likely to be minimal.

"The BBC HD channel is likely to deliver consumer benefits through increased take-up of HD, and pay satellite and cable platforms could benefit from increased subscriptions to their HD services," said Ofcom.

"Because the market positions of different broadcasters and TV service providers differ across platforms, we consider it a positive factor that the benefits are likely to be spread across all these major platforms."

Under the proposals the BBC will broadcast HD programmes on Freeview between 2am and 6am when spectrum is available.

But the corporation will be broadcasting nine hours of content a day by next year, and providing the same material to satellite and cable channels.

The BBC will eventually want to broadcast nine hours of HD content on Freeview, but this will not be possible until after the digital switchover is completed in 2012.

Ofcom also recommended that the BBC should look at ways to stream HD content over the internet once the necessary bandwidth becomes available.