Sky customers will be able to download TV content to mobile phones and tablets to watch even when they have no internet access.
The service expands on Sky's popular Sky Go, which allows users to stream content based on their Sky subscription.
For €6 per month, Sky will now allow up to four users to download on-demand movies and TV, including exclusive content such as the hit series Girls and the entire James Bond catalogue. Each download will last for a month, but users will be free to download as much as their device can hold. For some, this could mean up to 80 films or 400 TV programmes.
Sky claims that more than a quarter of its 11 million subscribers use Sky Go already, and believes that Sky Go Extra is the first mobile TV subscription service in the UK and Ireland to offer Hollywood movies to download and watch offline.
The WiFi-based platform is Sky's attempt to capitalise on the success of its on-demand offering. It claims that Sky customers time-shift around a fifth of all their TV viewing.
Luke Bradley Jones, Sky's brand director for TV products, added that when customers use on-demand TV they increasingly watch programmes from a wide range of broadcasters.
The Sky announcement increases the pressure on services such as Netflix, which does not have access to the vast array of content that Sky secures exclusively from movie studios, as well as the programmes it makes itself. Recently these have included David Attenborough's Galapagos and An Idiot Abroad, satrring Ricky Gervais, Karl Pilkington and Warwick Davis.
Sky claims that it offers around 70 of the top 100 films, around six months after their cinema release, and that this is more than its rival subscription services combined.
By Matt Warman, telegraph.co.uk