Seven set forth on a 21st-century adventure

Enid Blyton's novels are to be updated, re-illustrated and digitised now Hachette has the world rights. By Nick Clark

Enid Blyton has sold 600 million books worldwide (Rex Features)

Cripes! The Secret Seven are off on a new adventure. They are shelving the jolly japes and following the Famous Five into the digital age, taking modern dialogue with them on their travels.

Having modernised the Famous Five ahead of the quintet's 70th birthday this year, the publisher Hachette UK has snapped up the worldwide rights to Enid Blyton's entire estate, excluding Noddy, and plans to bring more of her most famous characters into the 21st century.

Marlene Johnson, the managing director of Hachette's children's books division, said that following the deal they had "great plans for the future". These plans include new illustrations and updated language, as well as making many more Blyton works available for digital download. In all, it will "catapult Enid Blyton into contemporary society", she said.

Hachette, which for some time has published the Famous Five under licence from Chorion, had already called in illustrators including Quentin Blake to "reinterpret" the intrepid child adventurers.

There was controversy when the language of the Five was updated last year, but more of Blyton's work, including The Secret Seven and The Naughtiest Girl novels, are now set to ditch their lashings of pop and jolly hockey sticks.

"We will look at all of the works," Ms Johnson said. "We modernised the Famous Five last year, amid much murmuring. But these days you don't talk of jolly japes to kids."

Despite an outcry, the company believes that a revamp could boost sales of the books – in which the stories remain unchanged – attracting kids who may have been put off by language they could not relate to.

There might even be a new Famous Five tale to tell, alongside the 21 existing adventures. Ms Johnson said that yesterday they stumbled across an original manuscript called Happy Christmas, Five. "I'm not aware of it being published before." There is a reference to a story of the same title in a Princess Gift Book for Girls but it is unclear whether it is the same.

Blyton, who died in 1968, was a prodigious writer, with Hachette estimating they now have the rights to over 800 of her novels and short stories. She also remains one of the most popular: having sold as many as 600 million books over the decades, last year Blyton was the 20th best-selling author in the UK by trade sales.

Hachette is going to push ahead with digitising her works, of which only about 50 are available for download.

Yet some of Blyton's books have been criticised for racism and elitism, perhaps reflecting another reason why the language is being updated. Michael Rosen, Children's Laureate between 2007 and 2009, has said: "I find myself flinching at occasional bursts of snobbery and the assumed level of privilege of the children and families in the books. Admittedly, this might go over the heads of the modern children reading now."

Ms Johnson said she was "absolutely delighted" to have secured the rights, adding the author's work was coming home to her original publisher Hodder, a subsidiary of Hachette.

She was sanguine that Noddy would not be following the Five, the Seven and friends onto her books: "Those books have never done particularly well in Britain," she said. "They were always much more popular in France."