Pre-orders for the sixth book in the Harry Potter series have " substantially exceeded" expectations, the title's publisher Bloomsbury said.
The latest instalment - called Harry Potter and the Half-Blood Prince - is not due for release until July 16, but already looks certain to build on the phenomenal success of previous titles from author JK Rowling.
Bloomsbury did not disclose sales figures, but said demand for the forthcoming hardback release would help leave 2005 profits far higher than hoped.
It is now looking for a surplus of at least £20 million, compared with the £18 million forecast by City analysts.
"Based on the pre-orders, the new Harry Potter will be a significant increase over the last one, which itself was the biggest launch of all-time," said chairman Nigel Newton.
"In the last two years, many new readers have come to the series and those people will be candidates for buying the new book."
Bloomsbury also announced results for 2004 yesterday, with profits up 6.9 per cent to £16.4 million - despite the lack of a new Harry Potter title in the year.
Aside from the continued adventures of the boy wizard, Bloomsbury has been buoyed by number one best-sellers in the world's three largest book markets during 2004 - Jonathan Strange and Mr Norrell in the United States, The Two of Us by Sheila Hancock in the UK and Schott's Original Miscellany in Germany.
It promised "significant progress" this year with new titles from John Irving and Ben Schott and paperback versions of some of its bestsellers likely to add to the profits boost from the Harry Potter release.
The optimism for the year ahead prompted Bloomsbury to offer shareholders a 47.8 per cent increase in its final dividend payout, to 2.478p a share.
Bloomsbury shares rose three per cent following the update. The company said sales from its reference titles increased by 11.4 per cent to £13.9 million, following the acquisition of Reeds Nautical Almanac in 2003.
Adult title sales were up by 64 per cent to £30.2 million.
The release of Harry Potter And The Order Of The Phoenix in 2003 meant sales of children's titles - accounting for half of all business - fell by 22.7 per cent to £40.4 million.
The integration of US group Walker Publishing, bought for an initial outlay of $6.5 million (£3.5 million) in December, was going "extremely well", with Newton pledging to use Bloomsbury's burgeoning cash pile on further acquisitions.
"We are open to acquisition to takeover opportunities ... but one has to pick the opportunities as they arise," said Mr Newton.