The seventh and final Potter book is due out in July

Reporting its 2006 results, its pre-tax profit dropped to �5.2m from �20.1m in 2005, when the most recent book about the teenage wizard was released.

The results were not a surprise as Bloomsbury warned in December that its full-year profits would be down.

The seventh and final Harry Potter book is set for release in July this year.

'Growth strategy'

Bloomsbury chairman Nigel Newton said 2006 was "a challenging year".

Its turnover for the year fell 32% to �74.8m from �109.1m in 2005.

Mr Newton said the firm now had a growth strategy in place that included developing new authors, internet-based initiatives, and acquisitions, "all of which we believe will enhance and strengthen our position as a leading publisher".

The global success of the Harry Potter books has generated bumper profits for Bloomsbury, but the company is now under pressure to find new hit publications as the Potter series draws to a close.

In previous years without a new Harry Potter release, the company has been able to continue to raise profits, thanks mainly to follow-up paperback sales or the books' global roll-out.

However, it now appears that these have both reached saturation point and that anyone who wants a current Harry Potter book has already got one.