BSkyB has signed a five-year deal for the exclusive rights to the entire HBO TV catalogue, which includes top American shows such as Girls and Game of Thrones, in a move that heads off a threat from arch-rival BT to enter the entertainment and film market.

BSkyB has struck early to extend its existing agreement out to 2020 in a deal worth as much as £275m over five years.

Sky TV satellite TV company has moved quickly to secure a wide-ranging two-pronged deal with HBO. HBO revolutionised the TV market by investing in big budget dramas such as The Wire and The Sopranos.

BSkyB airs the HBO catalogue on its heavily-promoted Sky Atlantic channel.

In addition BSkyB has also reached an exclusive agreement to co-fund and co-produce top-end dramas, of the scale of the multi-million pound per episode Game of Thrones, that could run to tens of millions of pounds investment in new shows per year.