The founder of Bloomsbury, which publishes the Harry Potter book series, has split his joint chairman and chief executive role to focus on strategy, stoking speculation about the company’s life after the boy wizard.

Nigel Newton has held the dual role of chairman and chief executive since setting up Bloomsbury in 1986. The company has now recruited Jeremy Wilson, the vice chairman of business banking at Barclays, to become its non-executive chairman.

Mr Newton famously decided to hand JK Rowling a £1,500 advance for her first Harry Potter book - Harry Potter and the Philosopher’s Stone - after his eight-year old daughter enjoyed the opening chapter.

Mr Newton will remain as chief executive and concentrate on how to position Bloomsbury ahead of a period a “significant change in the publishing industry”.

The move follows growing concerns in the City about how the group will prepare for a post-Potter future.

The company’s shares have more than halved since hitting 374p two years ago when the sixth Potter book was published. They were unchanged at 163.75p today.

It has developed an extensive list of other authors, including Germaine Greer, Joanna Trollope, Margaret Atwood and English Patient-prize winner Michael Ondaatje and is thought to have lined up a number of acquisitions.

Speaking today, Mr Newton said: “For some time I have been considering separating the roles of chairman and chief executive.

“I see this as useful in achieving Bloomsbury’s ambitions in the years ahead, allowing me to concentrate on the development and execution of Bloomsbury’s strategy during a period when we foresee significant change in the publishing industry.”

Mr Wilson has worked at Barclays since 1972. He has served on the Bloomsbury board as a non-executive director since 2005.

He said: “Bloomsbury is a remarkably successful company with a formidable publishing list, a wealth of talented individuals at all levels of the company. It is well positioned to take advantage of the opportunities now arising in the publishing sector.”

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