The world of children's publishing in the U.K. has been rocked by Bonnier's announcement Monday that Sarah Odedina has "decided to leave Hot Key Books.”

The news was as much of a bolt from the blue as the announcement, in July 2011, that Odedina was leaving Bloomsbury (where she had published the Harry Potter novels) to set up a then unnamed children's fiction list at Bonnier, the privately owned Swedish media group whose U.K. operation already included the illustrated children's publishers Templar and Autumn.

Richard Johnson, CEO of Bonnier Publishing, said, at the time of Odedina's hiring, that the company had high hopes for the new imprint. "We wanted to do it properly, and we weren't going to do it at all unless we were able to appoint a top person to the job, which we've done with Sarah," he said. "We talked to lots of people. We've got big ambitions."

The reasons for the departure were not clear, although there was talk in the trade yesterday that Hot Key had failed to meet stiff profit targets. Senior staff were reportedly in Dubai while Odedina herself was at home, and not in communication. The Bonnier statement said simply that Odedina would "remain at the company" until April 30, 2015, but will be stepping down from her position as managing director immediately.

The statement continued: "The search for her replacement has already started. In the meantime, it is business as usual at Hot Key Books and Bonnier Publishing, who remain fully committed to expanding their children's and YA fiction interests."

A spokesperson said there had been no falling out, and that the decision to leave was Odedina’s. All her authors will be reassigned to other editors, and Kate Manning is overseeing the imprint until a replacement is found.

Odedina began her career in rights, working first at Penguin Books before moving to Orchard Books as rights director. She joined Bloomsbury in 1997.

A version of this story originally ran in PW partner publication in the U.K., BookBrunch.