ITV HD will become ITV1 HD when it relaunches for Freeview HD from the end of this year.
Up to half of ITV1's peak-time shcedule will be simulcast in 'native HD' by 2010, increasing to 70 per cent by 2014, the broadcaster told investors.
The new channel will be part of the Freeview HD rollout, which begins in Granada on December 2, followed by London in late 2009 or early 2010.
Up to four other urban areas will also see ITV1 HD on Freeview in early 2010, followed by other UK regions as the Digital witchover timetable rolls around the UK.
Announcing its latest financial results, ITV said: "The simulcast service will exploit the power of the ITV1 brand, the familiarity of the audience with the architecture of the schedule as well as the fact that ITV invests 90 per cent of the ITV1 programme budget in the peak time schedule."
ITV estimates that almost half of UK homes will be able to see the HD channel by the time of the football World Cup in June 2010, said TV industry newspaper Broadcast.
ITV dramas already made in HD include Marple, Doc Martin, Kingdom and Lewis, and the South Africa World Cup will include 42 hi-def matches in ITV (and another 42 on BBC HD).
The announcement also implies that ITV has secured an affordable deal for carriage on the Freeview HD multiplex, which will be managed by the BBC.
Both ITV and Channel 4 had said the cost of broadcasting in HD on Freeview could be a problem because of declining advertising income.