Satellite broadcaster BSkyB says it has added 90,000 net new customers in the three months to the end of June, up by 17% on the same time a year ago.
Sky is being investigated over is share in ITV
The company added 349,000 new customers during the quarter, and now has 8.6 million customers.
It also said that "churn" - the number of customers leaving the service - had fallen to 12.1% from a previous 13.7%.
Sky, which has 716,000 broadband customers, is facing a competition probe over its 17.9% stake in ITV.
"Our transformation continues to gather pace," said BSkyB chief executive James Murdoch.
"Today we are adding new customers at the fastest rate since analogue switch-off; we are adding more broadband customers than any other provider; and we are the only major residential telephony provider growing its customer base."
The Competition Commission is currently investigating whether BSkyB's stake in ITV, allied to Mr Murdoch's other UK media interests, threatens diversity of news.
It will seek to establish if there is an "ownership link" between BSkyB, News International, publisher of The Sun, ITV and broadcast news provider ITN.
Rival broadcasters claim BSkyB's stake harms competition but it denies this.
The firm has also been involved in a long-running spat with Virgin Media, with the pair accusing each other of intransigence in a row that has led to Virgin customers losing channels.
Sky has pulled some of its channels from Virgin's cable TV service in a row over payment, leaving viewers unable to watch programmes such as Lost and 24.