Image caption JK Rowling wrote seven Harry Potter books

Author JK Rowling has announced her first adult novel will be called The Casual Vacancy.

The Harry Potter writer revealed in February that she was working on the book, and said it would be "very different" from her previous material.

The book will be published worldwide in hardback, e-book and as an audio download and CD on 27 September.

"The freedom to explore new territory is a gift that Harry's success has brought me," Rowling said.

The story is centred on the death of Barry Fairbrother, whose unexpected passing shocks the local villagers of Pagford.

Publishers Little, Brown & Co said: "Pagford is, seemingly, an English idyll, with a cobbled market square and an ancient abbey, but what lies behind the pretty facade is a town at war."

The company describes the tale as being "blackly comic, thought-provoking and constantly surprising".

Media playback is unsupported on your device Media caption JK Rowling speaking to the BBC about her future projects in 2011

Speaking at the premiere of the final Potter movie last year, Rowling told BBC News that the movie marked the start of a new writing direction.

"I think I always felt that I didn't want to publish again until the last film was out, because Potter has been such a huge thing of my life.

"I've been writing hard ever since I finished writing [Harry Potter and the Deathly] Hallows, so I've got a lot of stuff. And I suppose it's a question of deciding which one comes out first."

More than 450 million copies of Rowling's seven Potter books have been sold worldwide.

The novels, about a boy wizard who survives the attack that kills his parents, became a worldwide phenomenon and were turned into eight blockbuster films starring Daniel Radcliffe.

When the final instalment of the book series went on sale in 2007, thousands of copies sold in minutes.