Sky's share price has fallen 14 percent after it announced it lost 45,000 core residential subscribers over the past few months.
The pay TV company Sky Network Television had 860,445 customers at the end of December, but was expecting total subscriber numbers to fall by about 3.5 percent to 830,000 by the end of June.
Sky said the decline in core residential customers was anticipated following the roll-off of subscribers who signed on to watch the Rugby World Cup in 2015.
Meanwhile, it said Neon and FanPass have gained about 25,000 subscribers.
While the company said it was on track to meet the lower end of its profit guidance for 2016, it said the loss of subscribers would adversely impact next year's earnings, relative to a consensus of market expectations.
On the plus side, it said subscriber numbers were expected to get a bit of a boost with the Rio Summer Olympics in August and the Lion's Rugby Tour in June 2017.