LONDON — BSkyB added 171,000 subscribers in the three months ended March 31, bringing its customer base to 5.9 million.

The company’s third-quarter results showed a 15% rise in sales to £734 million ($1.07 billion). But it reported a pretax loss for the period of $45 million, reflecting a writedown of $32.6 million against the closure of ITV Digital and goodwill amortization of $42.6 million.

Overall, the third-quarter figures for the Rupert Murdoch-controlled satcaster were ahead of analysts’ predictions and confirmed its dominant position in the U.K. pay TV business.

The failure of ITV Digital and the ongoing financial difficulties of cablers NTL and Telewest have left BSkyB in an unchallenged position of market leadership.

Its churn rate — the rate at which customers cancel their subscriptions –is running at a healthy 10.5%, contrasting with a ruinous 30% figure suffered by ITV Digital before its demise.

BSkyB’s average revenue per sub is also growing strongly, up 11% in the first nine months to $545 per year.

BSkyB chief exec Tony Ball played down talk that the satcaster may bid for Channel 5, as permitted by the U.K.’s proposed new media ownership rules.