J.K. Rowling is back, and writing for adults

New York: The author of the mega-selling Harry Potter series has an agreement with Little, Brown in the United States and Britain to publish her first novel for grownups. The title, release date and details about the novel, long rumored, were not announced Thursday. Her seventh and final Potter story came out in 2007.

Rowling's Potter books, which broke sales records around the world, were published by Bloomsbury in Britain and Scholastic in the U.S.

Rowling will now share the same publisher with Stephenie Meyer, whose Twilight series at least partially filled the gap opened by the conclusion of the Potter stories.

"Although I've enjoyed writing it every bit as much, my next book will be very different to the Harry Potter series, which has been published so brilliantly by Bloomsbury and my other publishers around the world," Rowling said in a statement released by Little, Brown. "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."

Rowling's agent, Neil Blair, would not disclose financial details of the deal but said Thursday there had been no auction.

"As her new book is for a different audience, and marks a new literary direction for her, it made sense to separate the two and for her new book to be launched by a different publisher," said Blair.

In a statement, Bloomsbury said its 15-year relationship with Rowling "remains stronger than ever" -- and new editions of the seven Potter novels were on the way.

In the U.S., Scholastic spokeswoman Kyle Good noted that Scholastic didn't publish adult books.

"We will continue to publish her children's books in the U.S.," Good said Thursday.

Any Rowling book would seem a guaranteed million seller, although it's questionable that her new novel will have the same mass appeal as Potter. Adult authors from E.B. White to Sherman Alexie have nicely managed the transition to writing for young people, but once a writer is defined as a children's author, the transition can be tricky.

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. Margaret Wise Brown, author of the classic Goodnight Moon, tried for years to write stories for The New Yorker.

But Rowling does begin with one advantage: The Potter books had an enormous following among readers of all ages, and she is widely credited with revealing to publishers that children's books were no longer just for the young. Meyer's vampire novels and Suzanne Collins' Hunger Games trilogy also have caught on with both parents and their kids. Meyer herself wrote an adult book, The Host, a best-seller in 2008.

Beth Puffer, director of the Manhattan-based children's bookseller Bank Street Bookstore, said she'd have to see the novel before deciding where or whether to stock it.

"I assume if it's written for adults, it's not appropriate for children," said Puffer, who added that she might stock the book in a section for ages 14 and up. "There are a lot of former children and young adults who grew up with Harry Potter and they would likely be an audience for her new book. You also have all the adults who loved the Potter books."

Rowling's novel will be available in both print and electronic formats. The author held out for years on allowing the Potter books to come out digitally but announced in 2011 that Potter e-books would be sold through her own Pottermore website. The books were supposed to become available last fall but have been delayed until sometime this year.