Neil Gaiman and Terry Pratchett's fantasy comedy novel Good Omens is to become a TV comedy series.

A six-part comedy series is going into production, to be broadcast on Amazon Prime Video and the BBC in 2018.

Good Omens focuses on the story of an angel and demon who are trying to stop the Apocalypse. "According to The Nice And Accurate Prophecies of Agnes Nutter, Witch (the world's only completely accurate book of prophecies), the world will end on a Saturday. Next Saturday, in fact. Just before dinner.

"So the armies of Good and Evil are amassing, Atlantis is rising, tempers are flaring. Everything appears to be going according to Divine Plan. Except Aziraphale, a somewhat fussy angel, and Crowley, a fast-living demon - both of whom have lived among Earth's mortals since The Beginning and have grown rather fond of the lifestyle - are not actually looking forward to the coming war. And someone seems to have misplaced the Antichrist..."

Good Omens has previously been adapted as a Radio 4 series in 2014 starring Mark Heap and Peter Serafinowicz. Casting for the TV version has yet to be announced.

Terry Pratchett died in 2015, however Neil Gaiman (pictured) has adapted the book for television and will serve as showrunner on the production. He says: "Almost 30 years ago Terry Pratchett and I wrote the funniest novel we could about the end of the world, populated with angels and demons, not to mention an 11 year-old Antichrist, witch-finders and the four horsepeople of the Apocalypse. It became many people's favourite book. Three decades later, it's going to make it to the screen. I can't think of anyone we'd rather make it with than BBC Studios, and I just wish Sir Terry was alive to see it."

Chris Sussman, Head of Comedy at BBC Studios, adds: "Good Omens has always been one of my favourite books, and it's hugely exciting not just to be able to bring it to life, but to do so with scripts from Neil Gaiman himself. It feels like a good time to be making a comedy about an impending global apocalypse."

The BBC is collaborating with Amazon to fund the show, which is expected to require a large budget to bring the six hour long episodes to screen. Good Omens will be shown on Amazon Prime worldwide first, with the BBC showing it on television in the UK after that.

Mark Linsey, Director BBC Studios, comments: "This is a fantastic achievement that comes as we begin to grow our global customer base, and it demonstrates there is considerable appetite for BBC Studios to make programmes for other broadcasters once we launch as a commercial player. I'm delighted that this major production is with a writer of Neil Gaiman's stature and we look forward to developing more exciting, innovative projects like this in future."

Joe Lewis from Amazon Studios says: "Spanning not only the universe but also the entirety of time, Neil Gaiman has created a story that may be the largest ever told on television. We're excited to be working with BBC Studios to bring Neil and Terry Pratchett's incredible book to life and to Prime members everywhere."

Casting details are expected to be released as the show goes into production.