Harry Potter continued to cast his magic on publishers Bloomsbury Publishing, the group showed today as it reported a jump in sales and profits.

The release of Harry Potter and the Prisoner of Azkaban in paperback in April meant JK Rowling's series continued to be in the first, second, third and fourth position on many bestsellers lists, Bloomsbury said.

The fictional schoolboy's adventures helped turnover at the group for the six months to June 30 jump to £11.4 million, against £6.4 million last time. Profits came in at £273,000, against a loss last time of £103,000. As the latest book in the series, Harry Potter and the Goblet of Fire, was launched after the half-year end, its success will be seen in the group's full year figures.

However, the teenage wizard was not the only successful title launched by the group - others included Joanna Trollope's Marrying the Mistress and Michael Ondaatje's Anil's Ghost, his first novel since The English Patient.

From the paperback list, Ahadaf Soueif's The Map of Love sold more than 100,000 copies, while Anna Pavord's groundbreaking The Tulip sold more than 50,000.

Among Bloomsbury's children's titles, Holes, by Louis Sacha, helped the year off to a good start, running into the third print within two months.

The group said its US division was rapidly establishing itself as one of the most "progressive new publishing houses", while its reference and electronic media division continued to expand its database development.

Chairman Nigel Newton said: "The run up to Christmas will always have a major effect. Our excellent results for the first six months of this year are the start of greater things to come."