E-book sales accounted for over 8% of Pan Macmillan's trade sales in the first quarter of 2011, with the publisher predicting a rise to up to 10% by the end of the year.
Over the same period, the publisher's sales of print books have also shown "double-digit sales growth".
Pan Macmillan's rate of e-book sales has increased 15-fold, when comparing quarter one 2011 with quarter one 2010. The publisher now has 1,300 e-books available, up from 500 during the same period a year ago. Pan Mac highlighted Those in Peril by Wilbur Smith, Jeffrey Archer's Only Time Will Tell and titles by Peter James and Emma Donoghue as particularly successful e-book titles.
Pan Macmillan digital director Sara Lloyd said: "We're delighted with our strong e-book performance. Clearly the market is developing apace. We've capitalised on our ability to move fast to expand our customer base and proactively pursue the strategic promotional, packaging and placement opportunities that digital publishing affords us, to get ahead of the game."