THE creator of Harry Potter is back – but this time she is writing for adults.

It was confirmed last night that JK Rowling is to publish her first novel for grown-ups and has also changed publishers, from Bloomsbury to Little, Brown, which will produce her book in the UK and the US.

The Harry Potter series has sold more than 400 million copies worldwide and made the Scottish-based writer one of the literary world's most famous names.

The author said her new novel would be "very different" to the Harry Potter epics, although she insisted: "I've enjoyed writing it every bit as much."

Ms Rowling added: "The freedom to explore new territory is a gift that Harry's success has brought me, and with that new territory it seemed a logical progression to have a new publisher.

"I am delighted to have a second publishing home in Little, Brown, and a publishing team that will be a great partner in this new phase of my writing life."

The book, which has already been completed, will be published by Hachette in Australia and in New Zealand and other English-language markets.

As yet, mystery surrounds the novel. The title and date for the worldwide publication as well as further details about the book will not be announced until later in the year.

Her seventh and final Potter story came out in 2007.

Ms Rowling's Potter books were published by Bloomsbury in Britain and Scholastic in the US. David Shelley, publisher at the Little, Brown Book Group, said: "For me, quite simply, it is a personal and professional dream come true to be working with JK Rowling.

"She is one of the best storytellers in the world, and I am looking forward enormously to helping bring her new novel for adults to her fans and admirers, and to introducing her writing to new readers the world over."

Last year Ms Rowling ended her long-running association with the literary agent Christopher Little.

She had worked with Mr Little since the first Potter novel, Harry Potter and the Philosopher's Stone, in 1996.

She is now managed by Neil Blair, a lawyer and former partner at Mr Little's agency.

Mr Little, 69, was reported to have been "disappointed and surprised" by Ms Rowling's decision last year.

Yesterday Ian Rankin, the Scottish writer who, like Ms Rowling, is based in Edinburgh, teased fans on Twitter by hinting at a possible plot for the new book.

He said: "Wouldn't it be funny if JK Rowling's first novel for adults turned out to be a crime story set in Edinburgh? My word yes." He added: "She's certainly a fan of the traditional whodunit."

Mr Rankin's fellow crime writer Val McDermid said: "Nice to see that JK Rowling has such good taste in editors. I guess I'm willing to share David Shelley..."

The adult work will inevitably be compared to the Harry Potter saga, but is clearly aimed at a different audience, and will not be expected to replicate the overwhelming commercial success of the novels.

The cinematic adaptations of her magical tales have made more than £3 billion in box office receipts across the world.

The writer, whose personal wealth was estimated at £530 million in the latest Sunday Times Rich List, has spoken in the past about how much she missed her most famous character last year when she unveiled her website, Pottermore.

She admitted that working on the project, which has been in development for several years, allowed her to "stay in touch" with the period in her life when she was writing the stories.

She said: "It is true to say that finishing writing Harry, I have only cried that much, ever in my life, when my mum died.

"I've never cried for a man like I've cried for Harry Potter."