The BBC announced this week that it would simulcast high definition peaktime programmes from BBC1 on cable and satellite from the middle of next year, and would start London-based trials of a terrestrial HD service.
The announcement came as good news for Sky, which is planning to launch its high definition subscription-only service next year with the date to be confirmed. The BBC's HD service would be broadcast free-to-air, and so would be available through Sky's HD receiver.
Sky put the figure for the number of HD sets in Britain at 700,000, but said this figure would rise to two million by the end of next year - 8% of British households.
BSkyB's chief operating officer Richard Freudenstein said: "HD will bring a huge leap forward in picture quality when Sky's service launches on satellite next year. The BBC's commitment to HD is very positive news for this exciting technology and ensures that viewers will be able to enjoy an even wider choice of programmes in HD quality."
The BBC has pledged to start the trial on each platform "as they become viable", and expects the pilot to last a year.