The service will be free to watch with ads. An optional subscription tier – rumoured to be called ITVX 'Plus' – will serve up a "starry" premiere each week and 15,000 hours of content.
ITVX will replace both ITV Hub and ITV Hub+ when it launches later this year.
The broadcaster hasn't said hasn't said how much it will charge for premium membership, but the monthly fee for ITV Hub+, which allows members to watch ad-free, is currently £3.99.
ITVX Plus subscribers will also get access to the thousands of box sets on Britbox, which charges £5.99 a month and serves up the "biggest streaming collection of British TV ever".
The launch of ITVX is part of ITV's move towards a "digital first" strategy, which means that "much of its new content" will air first on ITVX before arriving on its linear TV channels "months later".
So, what will you be able to watch on ITVX? The service will launch with a host of big-budget originals including A Spy Among Friends starring Damian Lewis and Guy Pearce, Nolly starring Helena Bonham Carter, Litvinenko starring David Tennant and Sir Lenny Henry’s The Little Birds.
There will be 500 films available in the first year, plus 20 free (ad-supported) "themed" channels including 'True Crime', 'The Oxford Detectives' and '90s Favourites'.
"Our ambitions in the streaming world are not world domination," said Carolyn McCall, chief executive at ITV. "It is about being a national champion. It is compelling and our expectations of subscriber numbers have been modelled in a very realistic way."
With traditional TV advertising revenues dwindling as viewers switch to 'over-the-top' streaming services, ITV seems to be taking the "if you can't beat 'em, join 'em" route.
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