Lorna Tilbian, analyst at Numis, said the increase in new HD subscribers was “outstanding” and outstripped forecasts of about 310,000. Overall, Sky added 172,000 new customers to take its subscriber base to 9700,000
Mr Darroch said: “It has been another good quarter in what remains a tough environment, with more customers joining Sky and strong demand across our entire product range.
“The standout performance came in high definition TV with almost half a million [more] customers choosing Sky+HD”.
He said HDTV has proved so popular that the company will now only sell HD-enabled set-top boxes. Sky said selling the HD box as standard would further encourage take-up of the premium service and make it easier for standard definition customers to upgrade.
HDTV helped the group increase its average revenue per user (ARPU) by 11pc to £492.
However, the company conceded that it spent an extra £70m on marketing the HD service in its first-half.
Mr Darroch said the company is now pushing full steam ahead into the “next frontier” of television, with the launch of a dedicated 3D channel in pubs and clubs in April.
Sky will make TV history on Sunday when it broadcasts Arsenals clash with Manchester United in 3D.
Mr Darroch said the wonders of 3D television will be available at home from this autumn when it will launch a new channel broadcasting 3D sport, movies, documentaries and the arts.
“It’s a risk. It’s the next frontier.” Mr Darroch said. “[But], Avatar [James Cameron's 3D sci-fi epic] has changed everybody’s view of 3D.”
He refused to speculate about how many customers the broadcaster expects to sign up, but said demand for HD TV far outstripped analysts early expectations.
Revenue in the six months to December came in 10pc higher than last year, and at the top end of analysts’ forecasts, at £2.9bn.
Pre-tax profits for the period rose 29pc to £358m, compared to £276m in the same period a year earlier. The interim dividend, payable April 20, rises 5pc to 7.875p. The shares closed down 14 at 540p.
Mr Darroch said the company is considering whether to appeal last week’s ruling by the court of appeal that it must sell down its 17.9pc stake in ITV to below 7.5pc. He said Sky has been approached by several prospective buyers of the stake it bought for £940m in November 2006.