Bloomsbury hopes Sage will provide some magic

From The Prisoner of Azkaban to the Sage of Omaha: Bloomsbury is tipping Warren Buffett to take over from Harry Potter as the publisher's major money spinner.

Bloomsbury has felt the passing of the boy wizard. Half-yearly results published yesterday – the first with no magic from JK Rowling's super-bestselling wizard series, the last of which was published in 2007 – show both revenue and gross profit down, by 18 per cent and 10.9 per cent respectively.

But the outlook is confident, in part thanks to the world's richest man. The Snowball, an unauthorised biography of Mr Buffett by Alice Schroeder, a former insurance industry analyst, is being touted as a potential chart-topper when it hits the book shops at the end of next month. Although not officially sanctioned, the account is the product of unprecedented access to Mr Buffet, his papers and his family.

Other big hitters on the stocks are Just Me by Sheila Hancock, The Guernsey Literary and Potato Peel Pie Society by Mary Ann Shaffer, and the new JK Rowling, The Tales of Beedle the Bard, which will be released just before Christmas.

Despite revenue falls, the group's profit before investment income was up by 6.1 per cent to £3.5m in the six months to June. The period was also the best six months ever for the UK Adult division, and overall net cash balances were up by 13 per cent to £53.8m.

Nigel Newton, the chief executive of Bloomsbury, said: "We have had a good start to the year, with strong underlying sales growth and a strong cash generation." Notable successes in the period include Khaled Hosseini's The Kite Runner and A Thousand Splendid Suns, as well as Blanche Ebbutt's Don'ts for Husbands and Don'ts for Wives.

"We have started to successfully position the group for the next phase of development with an emphasis on bottom-line growth and cash-flow improvements," said Mr Newton. "We have eliminated expense in the value chain, renegotiated supplier terms and are seeing the strategy beginning to deliver strong performance."