JK Rowling during the launch of online website Pottermore in London June 23, 2011.[Photo/Agencies]

It may lack wizards and witches, but J.K. Rowling and her publisher are hoping her first novel for adults, "The Casual Vacancy," will have the magic touch.

The book's title was announced Thursday by Little, Brown & Co. along with a brief plot synopsis and publication date.

The publisher said the "blackly comic" tale of rivalry and duplicity in a small English town would be available worldwide on Sept. 27.

The book will be Rowling's first post-Potter effort. Her seven-volume saga about the adventures of a boy wizard became one of the most successful fictional series in history and led to a series of extremely popular films.

The new book, aimed at a grown-up audience, will be set in a seemingly idyllic English town called Pagford which is described as far more menacing than its pretty facade would indicate.

It opens with the sudden death of a popular man whose unexpected demise shocks the town. The battle for his seat on the local council sets off "the biggest war the town has yet seen," with rich people fighting poor, parents battling their teenagers, and wives in conflict with their husbands.

The publisher said the 480-page novel will be sold as an e-book and audio download as well as in traditional hardback form.

The seven Harry Potter novels have sold 450 million copies and have been translated into 74 languages.

Rowling's final Potter offering, "Harry Potter and the Deathly Hallows," was published in 2007. She published a short Potter spin-off collection of stories, "The Tales Of Beedle The Bard," in 2008.

Rowling said earlier this year she wanted to reach an adult audience, but kept the book's name and publication date secret until Thursday.

In the past, many successful children's writers have struggled to remake themselves as adult authors. Winnie the Pooh creator A.A. Milne, a successful playwright in his early years, once confessed that he was forced to say "goodbye to all that" after his beloved books about the bear and friends.

But Rowling has one advantage: the Potter books had a huge adult, as well as child, audience.

Jon Howells of British book store chain Waterstones said "The Casual Vacancy" would likely be the year's best-selling novel.

He said the synopsis came as a surprise and suggested similarities to the work of popular mystery writer Alexander McCall Smith and Mark Haddon, a children's writer who had a huge adult hit with "The Curious Incident of the Dog in the Night-Time."

"We were all expecting some sort of crime or mystery novel, but she has, refreshingly, surprised us all," Howells said.

"The plot sounds like it will have hints of Mark Haddon and McCall Smith, and the promise of black comedy is very beguiling."