Harry Potter publisher Bloomsbury Publishing saw its half-year sales jump as the firm continues to diversify its book list.

It said its sales lifted 11.6% to £52.7 million in the six months to the end of August compared to a year ago, as the group boosted sales by 45% at its educational and children’s unit.

The publisher said revenues in its educational and children’s division rose to £16.3 million, with books such as Paper Towns by John Green and and the new children’s editions of J. K. Rowling’s Harry Potter novels as strong performers.

It added its adjusted pre-tax profit lifted 11.8% to £1.9 million.

The firm said other key titles in the period were Miss Carter’s War by Sheila Hancock and Not Quite Nice by Celia Imrie.

It added sales in its academic and professional unit lifted 3% to £14.4 million.

Chief executive Nigel Newton said: “Our Children’s and Educational division has delivered an exceptional performance, generating sales that were up 45% on the prior year.

“We have started the second half with a strong publishing list. Traditionally, sales of trade titles peak for Christmas and sales of academic titles peak in the autumn at the beginning of the academic year. We therefore expect our sales to be significantly second-half weighted, as in the past.”

In the second half of the year Bloomsbury’s publishing list includes the illustrated edition of Harry Potter and the Philosopher’s Stone, Sweet Caress by William Boyd and River Cottage: Love Your Leftovers by Hugh Fearnley-Whittingstall.

Analysts at Investec said: “First half figures roughly as expected, with children’s sales very strong and above our forecast.”

The broker expects Bloomsbury to turn in pre-tax profit up 7.4% to £13 million in the full-year to February.